evolution review

1. How do biologists define evolution?

2. What is a population?

3. What islands were important to Charles Darwin's thinking on evolution?

4. Biogeography is how living things are distributed around the world. How was Darwin surprised by the the biogeography he observed on his trip around the world?

5. While fossils support the theory of evolution, we can't rely on the fossil record ever being complete. Why?

6. How does the existence of fossils support the theory of evolution?

7. How did LaMarck explain inheritance?

8. What was the hypothesis of catastrophism?

9. While the theory of evolution does not indicate humans came from chimps, it does indicate a _________________________ between chimps and humans.

10. Upon what observations did Darwin base his theory of evolution by natural selection?

Review for 4th exam

1. What are two important factors in determining what type of Biome one will find in a given area?

2. What causes the seasons here in North America?

3. What are three strategies plants have developed to survive in the cold dry,and sometimes dark conditions of the Tundra?

4. What kind of adaptations have animals developed to survive in:
A. The tundra
B. The deserts


5. What is a rain shadow, and how does it account for different plant communities occurring at the same latitude, but on opposites sides of a mountain range?

6. In what biomes does fire play an important role, and what is this role?

7. How are coniferous forests different from deciduous forests?

Population Ecology and Interactions

1. Define resource partitioning and give an example of it.

2. How is a parasite different from a parasitoid?

3. How is a parasite different from a predator?

4. How are density dependent limiting factors different from density independent limiting factors? Give examples of each.

5. Define and give examples of the following: Mutualism, Commensalism, social parasite.

6. What are common strategies predators use to capture prey, and common defenses found in prey?

7. Draw a food web that could occur in your backyard or here at Cerritos. Include all the trophic levels we discussed in class.

8. Why are there fewer members of the upper trophic levels as compared with primary consumers or the producers?

9. What is carrying capacity?

Global Warming, Ozone loss, acid rain

1. What types of gases trap heat in the atmosphere? What are the sources of these gases?

2. What are some consequences of global warming?

3. What gases contribute to acid deposition?

4. What are the sources of the gases in question 3?

5. How has the problem of acid rain been reduced in the US?

6. What are the consequences of acid deposition?

7. What causes the seasonal loss of ozone in the antarctic?

8. Where is the ozone layer and why is it important?

9. What has been done to solve the problem of ozone loss?

Here's some questions to make those brain cells churn out the ATP!

1. What are the differences between aerobic and anaerobic respiration, and which is more efficient?

2. What are NAD+ and FAD used for?

3. What are the three steps in aerobic respiration, and where does each occur?

4. During which step of cellular respiration is the most ATP made?

5. During aerobic respiration, how many ATPs are made from one molecule of glucose in most cells?

6. What is the role of oxygen in aerobic respiration?

7. Describe how the ATP is made during chemiosmosis

8. What is produced by your muscle cells if there is not enough oxygen available at the end of glycolysis for aerobic respiration to continue?

9. Yeasts do a kind of anaerobic respiration called ____________, and produce ___________ and _________ along with 2 ATP

10. What are the important end products of the Citric Acid Cycle, and what happens to each of these products?



Here are the photosynthesis questions for review:

1. Which colors of light are most strongly absorbed by chlorophyll?
2. How is oxygen released during photosynthesis?
3. Why is water needed in photosynthesis?
4. What are the products of the light dependent reactions?
5. What is made in the light independent reactions?
6. What is the role of RUBP in photosynthesis?
7. What kind of plants use PEP and what advantage does it give them?
8. How are CAM plants different from others in the way they do photosynthesis?
9. What kind of organisms can do photosynthesis?
10. Where inside the chloroplast do the light dependent reactions happen?

More Review Questions about Plants:
1. Compare and contrast the movement of water and food in plants. Include in your answer what kinds of tissues and processes are involved in both.

2. Xylem is functional when dead at maturity while phloem is functional only when alive. Why?

3. In phloem, what is the role of the companion cell?

4. What is the difference between xylem in flowering plants and the xylem found in gymnosperms?

5. What is cohesion of water, and how is this different from adhesion?

6. What part of the root absorbs water?

7. What is the function of the anther in the flower?

8. Which of the following is where one would find ovules?
A. in an anther
B. in the ovary
C. in the stigma
D. in the style

9. Ovules are
A. eggs
B. spores that will become pollen
C. spores that will become eggs
D. immature seeds
E. pollen grains

10. In double fertilization the first sperm fertilizes the egg and the second
A. dies
B. is only used if the first sperm cell dies
C. fertilizes another egg
D. fertilizes a haploid endosperm mother cell to make diploid endosperm
E. fertilizes a diploid ( n+n) endosperm mother cell to make triploid endosperm

11. What is the function of fruit?

12. Microspores become
A. the embryo sac
B. the mature male gametophyte
C. pollen grains
D. all of the above
E. only B and C above

340 Native Plants in the Ground and Watered Today!

Thanks to everyone who came out today!


We planted over 340 native plants including bladder pod, coastal sagebrush, buckwheat, and black sage today. We also saw some wildlife up close...

This gopher snake may have been the owner of the snake skin we found while working. We also saw lizards, and ground squirrels. The weather was really pleasant for working. It turned out to be cool, not as hot as I had thought it would be! Later in the morning a think layer of fog rolled in as well.

Mitosis and Meiosis Review

1. If a cell has 8 chromosomes and does mitosis, how many cells will be made, and how many chromosomes will each cell have?

2. If a cell has 8 chromosomes and does meiosis to make sperm cells, how many cells will be made, and how many chromosomes will each cell have?

3. Mitosis creates cells which are ________, while meiosis makes cells which are _____.

4. What are homologous chromosomes?

5. What are sister chromatids?

6. What is crossing over, and during which process, (mitosis or meiosis) does it occur?

DNA Review

Here are some review questions about DNA from the lecture today.

1. Describe the structure of the DNA molecule

2. If the sequence of bases on one stand of the molecule is AAC TGC CCG, what is the sequence on the complemetary strand?

3. During DNA replication, what enzyme breaks the hydrogen bonds between the base pairs, and what enzyme matches up nucleotides to the existing ones on the parent strand of DNA?

4. Why is this type of replication called Semi Conservative?

5. How is RNA different from DNA?

6. The production of messenger RNA from DNA is called ________, and this happens in the __________ of the cell.

7. The parts of the mRNA molecules which are edited out before RNA reaches the cytoplasm are called __________

8. mRNA gets a cap and a tail prior to being read by the ribosome. What is the function of the cap and tail?

9. If the DNA strand being copied had this sequence: ACT GGC ATA CTA what would the sequence of the mRNA be?

10. The function of transfer RNA is ?

11. What is the name of the enzyme that produces RNA from DNA?

12. If the sequence of DNA is the same in your body cells, why are all cells not the same?

13. The DNA in you, an earthworm, and a fungus is the same. So why are you a human and not an earthworm?

14. What is an anti-codon and where is it found?

15. The protein synthesis process that occurs at the ribosome is called _____________

16. What is a stop codon?

Let's Rap About Genes ( and DNA while we are at it)

Coastal Clean Up Day at Bolsa Chica

Thanks to all who came out today to water and weed out non-native plants. There were so many people we were done in record time!

Review for 1st Exam Bio 120

Hi Folks,
These questions appear elsewhere on the blog, but I have brought them up in a current post so they are easy to find.

1. A cell must maintain an imbalance of sodium ions on either side of the membrane for it to function. What process would it most likely use of the ones we discussed in class?
2. How are polar and non polar covalent bonds different?
3. What is a hydrogen bond, and why are these bonds important to life?
4. Oxygen has 8 electrons, with 6 in the outermost energy leve. Will this atom react?
5. How are ions formed?
6. A solution with a pH of 5 is how many times more acidic than a solution with a pH of 7?
7. What determines if an atom with react with another?
8. A plant cell in a hypertonic solution will under go _____________
9. An animal cell in a hypotonic solution may undergo _____________
10. A Paramecium can survive in fresh water without bursting. Why?
11. How are the mitochondria and chloroplasts similar?
12. Why do we think the mitochondria was once an independent organism?
13. Describe the plasma membrane. Include how a lipid membrane functions in a watery environment.
14. What role do the proteins in the plasma membrane play?
15. How is active transport different from diffusion and osmosis, and faciliated diffusion?
16. How is dialysis different from osmosis?
17. What affect would a hypertonic solution have on a cell?
18.How is a hypothesis different from a theory?
19.What are five characteristics of living things?
20.How are prokaryotic cells different from eukaryotics cells?
21.What can cyanobacteria do that the bacteria living in your mouth do not do?
22.How are archebacteria different from the bacteria living on your skin?
23.Describe briefly what organelles would be involved in making a protein and exporting it from the cell.
24.Give an example of two cell organelles working together to accomplish a task.
25.What organelle is found on the ER?
26.What is the function of lysosomes?
27.Where is the nucleolus, and what is its function?
28.What are the functions of the Golgi bodies?

Chapter 3
1. What are the building blocks of carbohydrates?
2. What is the difference between a saturated and unsaturated fatty acid?
3. Why is the shape of an enzyme important to the function of the enzyme?
4. At what level of complexity do proteins usually become functional?
5. What makes up a nucleotide?
6. What bond forms between amino acids as they react to form proteins?
7. How is the function of carbohydrates different in plants and animals?
8. What is the name of the carbohydrate human cells use to store glucose?
9. Which of the macromolecules we discussed stores energy in the most efficient way?
10. What is the most common steroid in the body?

New type of Malaria vaccine in the works

Researchers from Johns Hopkins, Walter Reed, and the Institute of Primate Research in Kenya are developing an innovative vaccine against malaria. Malaria is a disease caused by a parasite (Genus Plasmodium) that invades the liver and red blood cells. The disease kills about one million people world wide each year and there are over 245 million people infected world wide.

The parasite spends part of its life cycle in humans, and part of its life in mosquitoes, and is spread from human to human via a mosquito bite from the female Anopheles mosquito.

Rather than preventing the transmission of the parasite from mosquito to humans, this vaccine prevents the transmission from human back to the mosquito. The vaccine won't help someone who is already infected, but could stop the spread of the disease through a community if the parasite can't get from infected humans back into the mosquito.

The researchers used genetically modified bacteria to make proteins found on the parasite during different stages of its sexual development, and then injected those into mice. The mice made antibodies against these proteins. The binding of the antibodies to the proteins on the parasite, stopped the parasite from reproducing.

After the mice received a booster shot transmission was reduced from mice to mosquitos by 98%.


You can read the entire article here

One of my weaknesses

I just love Cnidarians-the entire Phylum. I saw this video on PZ Meyer's Pharyngula blog and had to share this with you. It was shot at the fabulous Monterey Bay Aquarium by Eugenia Loli-Queru

Drifters of the deep from Eugenia Loli-Queru on Vimeo.

Polar Bears and Global Warming

Want to hear a polar bear breathing? Take a listen here.

National Public Radio had a story this morning about the polar bear monitoring that scientists with the US Fish and Wildlife Service are conducting. Take a listen to hear about the trouble these giant bears are having as the sea ice they depend on melts during the summer.

The H1N1 ( Swine flu) virus

The H1N1 virus. Photo from the CDC

Want to know about the flu?

Want to know how flu gets named, its ecology, how it evolves, or is trasmitted?
Check the fluwiki here.

Swine flu cases continue to rise

The CDC now reports 91 confirmed cases of swine flu in the US including 14 in California. Most likely, cases will continue to rise over the next few days and weeks.

The World Health Organization has raised raise the current level of influenza pandemic alert from phase 4 to phase 5 which means the organization thinks a pandemic is imminent. You can take a look at the WHO's definitions of the different levels here

Remember, frequent hand washing and the use of hand sanitizers will help reduce your chances of getting sick.

Swine flu update

The CDC is now reporting 64 cases of the swine flu in the US.

Here are recommendations from the CDC's website

What You Can Do to Stay Healthy

There are everyday actions people can take to stay healthy.

• Cover your nose and mouth with a tissue when you cough or sneeze. Throw the tissue in the trash after you use it.
• Wash your hands often with soap and water, especially after you cough or sneeze. Alcohol-based hands cleaners are also effective.
• Avoid touching your eyes, nose or mouth. Germs spread that way.

Try to avoid close contact with sick people.

• Influenza is thought to spread mainly person-to-person through coughing or sneezing of infected people.
• If you get sick, CDC recommends that you stay home from work or school and limit contact with others to keep from infecting them.

Swine flu update

Here are the most recent numbers of laboratory confirmed cases of swine flu in the US as reported on the CDCs website

California 7 cases
Kansas 2 cases
New York City 28 cases
Ohio 1 case
Texas 2 cases
TOTAL COUNT 40 cases

Swine flu

Why is this influenza virus called the swine flu? Its called swine flu because one of the proteins on the surface of the virus is most similar to those found on viruses that affect pigs. However this one is infecting people, not pigs. You can not get this flu from eating pork. It is spread from one person to another. The symptoms include high fever, aches, coughing and congestion.

There are anti-viral drugs like Tamiflu and Relenza that can combat this virus, and they are most effective if you start treatment early. So if you develop symptoms you need to get treated as soon as possible, and avoid contact with other people.

According to the Centers for Disease Control (CDC), twenty cases have been reported in the US including people from California, New York, and Ohio. Only one person was sick enough to be hospitalized. Canada has also recently reported a case. No one in the US has died of the disease as of yet, but over 80 people in Mexico have died.

One of the best ways to avoid infection is to frequently wash your hands. If you are sick, don't go to work, or come to school!

You have also probably heard the word "pandemic" in the news reports about this virus. The word pandemic comes from the Greek words for "all people", and is a disease that spreads across a large area, or even the world.

There are alot of blogs, and news organizations covering this right now. Here are a few links you can check for more information.

Here is the CDC's website on swine flu. It will be updated at least once a day.

Tara Smith is a Professor of Epidemiology and blogs about causes and evolution of diseases on her blog Aetiology

The editors of Effect Measure are public health scientists.

National Parks

PBS is broadcasting a new series this fall about our National Parks. Where have you been?

Surprise , Surprise , Surprise

The New York Times is reporting that a group called the Global Climate Coalition, an industry group that spent millions of dollars advertising that global warming was not was not "well understood", ignored their own scientists. Why? Because the scientists told them the truth-what they didn't want to hear. So while this group,which was made up of oil,coal,and car companies, was involved in advertisement and lobbying to convince folks their emissions were not to blame for global warming, their scientists were telling them just the opposite.

Here's a quote from the article taken from an internal report written by their scientists:
“The scientific basis for the Greenhouse Effect and the potential impact of human emissions of greenhouse gases such as CO2 on climate is well established and cannot be denied,” the experts wrote in an internal report compiled for the coalition in 1995.

At the same time the group was sponsoring advertisements that stated "the role of greenhouse gases in climate change was not well understood." Riiiight....

This reminds me of the executives of the tobacco industry claiming they didn't know nicotine was addictive....

Take a look at the article here

New Discovery in Seal Evolution

photo by Alex Tirabasso/Canadian Museum of Natural History

A newly describe fossil from the arctic sheds new light on seal evolution. The fossilized remains of Pujilla darwini indicate the animal walked on land,and had webbed feet, but not flippers. The early seal is estimated to be 23 million years old, and is the oldest fossil found yet of seal ancestors.

The species name honors Charles Darwin who predicted that marine mammals would be found to have evolved from land animals. It also appears that this early seal ancestor lived in fresh water, which is something Darwin had also predicted.


Read more about this discovery here

The Bolsa Chica Project- Video 3

Earth Day at Bolsa Chica

April 18th was a great day for community involvement, and a great day at Bolsa Chica.
Jim Sugra has done yet another great video about Bolsa Chica. Take a look. Are you in the video?

Earth Day Celebration at Bolsa Chica

Wow! We had over 300 volunteers out at Bolsa Chica today to help plant native plants, and participate in a beach clean up.



Thanks so much to everyone who helped at Bolsa Chica this planting season. Believe it or not, we put in 1,000 native plants today alone! It was a warm sunny day, just beautiful!

Smithsonian Institute National Museum of Natural History Washington D.C.

Spring break usually finds me camping somewhere in southern Utah, miles away from any large city. Not this year however, I took my grand-daughter to Washington D.C. Washington besides the obvious political attractions has the Smithsonian Museums. My favorite ( surprise, surprise) is the museum of Natural History, (although the Air and Space Museum is really cool too.)

Wow! What a Museum! T-Rex! These dinosaurs were big animals! Although I have read recently a hypothesis that suggests they were more scavengers than hunters. The hypothesis is they were big and scary looking to frighten the actual hunters away from the kills, so T-Rex could eat the kills of the other animals in peace.


ooohhhh... from a big dinosaur to a little one.... Archaeopteryx is a transitional form between reptiles and birds. Do birds have bones in their tails? Nope. Do they have teeth in jaws? Nope. Do they have claws on their wings? Nope. (Well one species still does, but only as chicks>) So they why is this fossil a bird? Look at the impression of the feathers. Birds have feathers. This fossil also has a "wishbone" just like chickens and turkeys.


This lovely fossil is of an Ammonite. Ammonites are related to modern day Mollusks like the nautilus, squid and octopus. They were a very diverse group of animals during the Cretaceous Period 144-65 million years ago. They are about 10,000 different species that have been identified.


So what's this lumpy looking fossil? It's one of the first trees! This is a fossil of a plant called Eospermatopteris. These trees grew to a height of about 40 feet. This early tree is about 345 million years old.




This tree is about 100 years old. The cherry trees near the Jefferson Memorial were in full bloom, and just beautiful when we first arrived. It rained a couple days later and the trees lost a lot of their blossoms.

Cherry trees near the Washington Monument

Trees in full bloom around the tidal basin

Review Exam 3

Here's some questions to make those brain cells churn out the ATP!

1. What are the differences between aerobic and anaerobic respiration, and which is more efficient?

2. What are NAD+ and FAD used for?

3. What are the three steps in aerobic respiration, and where does each occur?

4. During which setop of cellular respiration is the most ATP made?

5. During aerobic respiration, how many ATPs are made from one molecule of glucose in most cells?

6. What is the role of oxygen in aerobic respiration?

7. Describe how the ATP is made during chemiosmosis

8. What is produced by your muscle cells if there is not enough oxygen available at the end of glycolysis for aerobic respiration to continue?
9. Yeasts do a kind of anaerobic respiration called ____________, and produce ___________ and _________ along with 2 ATP

10. What are the important end products of the Citric Acid Cycle, and what happens to each of these products?



Here are the photosynthesis questions for review:

1. Which colors of light are most strongly absorbed by chlorophyll?
2. How is oxygen released during photosynthesis?
3. Why is water needed in photosynthesis?
4. What are the products of the light dependent reactions?
5. What is made in the light independent reactions?
6. What is the role of RUBP in photosynthesis?
7. What kind of plants use PEP and what advantage does it give them?
8. How are CAM plants different from others in the way they do photosynthesis?
9. What kind of organisms can do photosynthesis?
10. Where inside the cholorplast do the light dependent reactions happen?

More Review Questions about Plants:
1. Compare and contrast the movement of water and food in plants. Include in your answer what kinds of tissues and processes are involved in both.

2. Xylem is functional when dead at maturity while phloem is functional only when alive. Why?

3. In phloem, what is the role of the companion cell?

4. What is the difference between xylem in flowering plants and the xylem found in gymnosperms?

5. What is cohesion of water, and how is this different from adhesion?

6. What part of the root absorbs water?

7. What is the function of the anther in the flower?

8. Which of the following is where one would find ovules?
A. in an anther
B. in the ovary
C. in the stigma
D. in the style

9. Ovules are
A. eggs
B. spores that will become pollen
C. spores that will become eggs
D. immature seeds
E. pollen grains

10. In double fertilization the first sperm fertilizes the egg and the second
A. dies
B. is only used if the first sperm cell dies
C. fertilizes another egg
D. fertilizes a haploid endosperm mother cell to make diploid endosperm
E. fertilizes a diploid ( n+n) endosperm mother cell to make triploid endosperm

11. What is the function of fruit?

12. Microspores become
A. the embryo sac
B. the mature male gametophyte
C. pollen grains
D. all of the above
E. only B and C above

Bolsa Chica and the heartbreak of ORA-83

Bolsa Chica is home to an archeological site of National significance. Part of it was destroyed by the development of the housing at on the Bolsa Chica Mesa, but part of it can still be saved. Please watch the video to find out more...

The Bolsa Chica Project!

As you may know I am involved with a group called the Bolsa Chica Land Trust. Our goals is the preservation, restoration, and maintenance of the entire Bolsa Chica ecosystem. We have a plan to raise 5 million dollars in ONE DAY- EARTH DAY 2009. Check out the video to see how:


Did you like the video? If so sign up at Youtube, and comment on it and rate it! After signing in at Youtube just search "Bolsa Chica Project" to get to the video. You can also subscribe to get updates as there are more videos planned. Please share the video with your friends! This is a great way to spread our message and generate interest in the video.

More review questions for second exam

Genetic Engineering

1. What are restriction enzymes?
2. What kind of cells have restriction enzymes, and what is the purpose of these enzymes in the cell?
3. What is a plasmid?
4. How are plasmids used in genetic engineering?
5. Why does human DNA work in a bacterial cell?
6. What is gene therapy? Thursday, September 25, 2008

DNA Review Questions

1. Describe the structure of the DNA molecule

2. If the sequence of bases on one stand of the molecule is AAC TGC CCG, what is the sequence on the complemetary strand?

3. During DNA replication, what enzyme breaks the hydrogen bonds between the base pairs, and what enzyme matches up nucleotides to the existing ones on the parent strand of DNA?

4. Why is this type of replication called Semi Conservative?

5. How is RNA different from DNA?

6. The production of messenger RNA from DNA is called ________, and this happens in the __________ of the cell.

7. The parts of the mRNA molecules which are edited out before RNA reaches the cytoplasm are called __________

8. mRNA gets a cap and a tail prior to being read by the ribosome. What is the function of the cap and tail?

9. If the DNA strand being copied had this sequence: ACT GGC ATA CTA what would the sequence of the mRNA be?

10. The function of transfer RNA is ?

11. What is the name of the enzyme that produces RNA from DNA?

12. If the sequence of DNA is the same in your body cells, why are all cells not the same?

13. The DNA in you, an earthworm, and a fungus is the same. So why are you a human and not an earthworm?

14. What is an anti-codon and where is it found?

15. The protein synthesis process that occurs at the ribosome is called _____________

16. What is a stop codon?

Mitosis and Meiosis Review Questions

1. If a cell has 8 chromosomes and does mitosis, how many cells will be made, and how many chromosomes will each cell have?

2. If a cell has 8 chromosomes and does meiosis to make sperm cells, how many cells will be made, and how many chromosomes will each cell have?

3. Mitosis creates cells which are ________, while meiosis makes cells which are _____.

4. What are homologous chromosomes?

5. What are sister chromatids?

6. What is crossing over, and during which process, (mitosis or meiosis) does it occur?

7. Why is crossing over important?

8. During __________ of mitosis sister chromatids separate.

9. During _________ of meiosis homologous pairs of chromosomes separate, but during ____________ of meiosis sister chromatids separate.

10. In meiosis, typically four sperm cells are made, but meiosis only makes one large egg cell. Why?

Massive Cache of Fossils Unearthed at La Brea Tar Pits

Scientists at the La Brea Tar Pits in Los Angeles are in the process of sorting through a massive collection of fossils removed from near the LA County Museum of Art which is next to the tar pits. 23 crate loads of deposits were removed with a crane prior to the site being readied for an underground parking garage.

Since the summer of 2006, scientists working at the Page Museum have been sorting through the deposits. One remarkable find is that of an intact Colombian mammoth ( named Zed) which is estimated to be about 40,000 years old.

Other fossils include American lion bones, horses, bison, coyotes, lynx, ground sloths and dire wolves. The deposits are being uncovered by the staff at the George Page Museum. The lab where this is happening is surrounded by windows, so if you want to go watch take a visit to the Page Museum. You can visit the Museum's webpage here.

To read more and see a picture of Zed's pelvis, click here. KNX news radio also has pictures on their website here

Valentines Advice from Sage Grouse

Gail Patricelli from the University of California at Davis has discovered that to impress the ladies male sage grouse need more than a fancy dance and a big tail. The most successful males also responded to the behavior of females in subtle ways.

Groups of male sage grouse strut, inflate air sacs and make booming sounds in a complicated dance on a dancing area called a lek, while they compete for the attention of the females. Dr. Patricelli studied these behaviors with a camera ("called the fembot") disguised as female grouse. She found the few males which were successful in mating were those who were the most responsive to signals from the females.

So gentlemen, take a lesson from the sage grouse, and try a little sensitivity.
Take a look at the sage grouse display and the "Fembot" below

Post Darwin: Homer Simpson evolves

One of my friends posted this on his blog, and it is too good not to share with all of you. Enjoy

Happy Birthday Mr. Darwin

What concepts did Darwin develop, and why were they so revolutionary?

Species can change- Living things are not fixed, but can change over many generations.

Common Descent—All life on Earth shares a common ancestry. Yes, even humans.
Drawing from one of Darwin's notebooks

Gradualism--The change of a species takes a long time.
Marine Iguana, Isabela Island, Galapagos

Land Iguana, North Seymour Island, Galapagos.
The land iguana and marine iguana evolved from a common ancestor, probably an iguana from the mainland of South America.

Natural selection
Certain randomly acquired traits are helpful.

Individuals with helpful traits survive longer, have more offspring, so over time these traits increase in a
population.

Nature selects which traits are beneficial, and which are not.

Small ground finch, San Cristobal Island, Galapagos

Medium ground finch, San Cristobal Island, Galapagos.

The main difference between "Darwin's finches" is the size and shape of their bills. What advantage would their be to an individual with a beak like the one found on the medium ground finch? What about the the bill found on the small ground finch?

Others prior to Darwin had suggested species may have changed over time, and were not fixed. However, Darwin was the the first to suggest a logical mechanism (natural selection) though which these changes occurred.

Happy Darwin Day

Have you googled today? If you have then you might have noticed the tribute to Mr. Dawin. I see some of "Darwin's finches", from the Galapagos Islands in the illustration. When Darwin collected the birds, he actually thought he had a mix of finches, blackbirds, and warblers only to discover after the birds were examined back in England, by ornithogist John Gould that indeed they were all finches.

The bird that really go his attenion in the Galapgos were the mockingbirds on different islands.

Darwin wrote in The Voyage of the Beagle:
"My attention was first thoroughly aroused, by comparing together the numerous specimens, shot by myself and several other parties on board, of the mocking-thrushes, when, to my astonishment, I discovered that all those from Charles Island belonged to one species (Mimus trifasciatus); all from Albemarle Island to M. parvulus; and all from James and Chatham Islands (between which the other two islands are situated, as connecting links) belonged to M. melanotis."

He also noticed that the different species did not occur together on the various islands he visited and he wondered why this was...

Darwin Day Special: Evolution of Lice

Pubic louse (Pthirus pubis)

Biologists wonder about all kinds of things. Dr. Robert Weiss for example wondered why humans are parasitized by two different species of lice, head lice (Pediculus humanus) and pubic lice (Pthirus pubis commonly called crabs). What would have caused this separation of lice into two species, both of which occupy different habitats on the body? After all our ancestors were hairy all over so why specialize in different areas of the body?

Head louse (Pediculus humanus)



It turns out Dr. Weiss discovered pubic lice that infect humans evolved from lice found on gorillas (Pthirus gorillae). The two species of lice diverged about 3.3 million years ago according to David Reed from the University of Florida, however humans and gorillas diverged earlier, about 7 million years ago. Dr. Reed's work also demonstrated that human head lice probably came from our hominid ancestors. Dr. Weiss hypothesizes that later our human ancestors caught the pubic lice ancestor from the gorillas while hunting and butchering them. This close contact would have allowed the gorilla lice to jump onto our ancestors, burrow in and start feeding!

Weiss et al. Apes, lice and prehistory. Journal of Biology, 2009; 8 (2): 20 DOI: 10.1186/jbiol114

Darwin Day Special: Links

I've come across a couple of websites of interest to those of you who wish to learn a bit more about Charles Darwin.

This site by David Leff, has an amazing amount of information about Darwin the man as well as Darwin the scientist.

The complete works of Charles Darwin are online. This is a wonderful resource for exploring some of his letters, books and other publications

Darwin Day Special: More from Sir David Attenborough

This is a clip from the trailer of the new series, and a bit of a preview in which Sir David talks about one of the most compelling parts of Darwin's theory-that is that we, as humans, are not separate from the natural world, but part of it.

Darwin Day Special: from Dinos to Turkeys

Darwin Day Special: National Geographic's new show "Morphed"

National Geographic is broadcasting a series of shows this week as part of a new series called "Morphed" You can visit the website here, and watch short video segments about whale evolution, the evolution from dinosaur to birds, and bear evolution.

I watched the video clips, and did cringe a bit when in the one about the transition ancestors of whales underwent from land animals to marine animals, the narrator talks about a paleontologist "going after the biggest fish in the sea." Whales, after all are mammals like you and me, not fish.



There is a great deal of information on the website including a short preview of a program on Darwin's notebooks that includes a re-enactment of Darwin in Patagonia.

The series starts broadcasting tomorrow.

Darwin Day Feb. 12 Happy 200th Birthday to Charles Dawin

In honor of the 200th anniversary of the birth of Charles Darwin, I will be posting information about evolution over the next week or so. Remember, come to the Darwin Day presentation on Feb 10 at 11 AM in Science Lecture hall 201.

Darwin Day Special: OK so flies evolve... but what about people

In my last post I wrote about work that demonstrates the evolution of fruit flies over a period of a couple of hundred years. This kind of research shows us we can look around at the living world and see evidence that evolution is happening around us, but what about us? Are there things in our bodies that hint at our evolutionary past?

Why do we have parts in our bodies that don't function? Why do we have things like goose bumps, which don't do anything for us? Structures present in an organism, but not functional (even though these structures may function in other organisms) are called vestigial structures.

What is responsible for the construction of vestigial structures during development? Sequences of DNA.
Where does DNA come from? Our ancestors......

For a list of vestigial structures found in humans click here.

Darwin Day Special: Flies that live on apples providing more clues to formation of new species

Biologists from Notre Dame, Michiagan State and the University of Florida have just published an article in which they describe how the introduction of apple trees to the US 400 years ago has affected the evolution of a type of fruit fly AND the parasitic wasp that feeds on the maggots of the fly.

Prior to the presence of apple trees in the US, these flies Rhagoletis pomonella found mates, and laid eggs on the fruit of the hawthorn tree. In the 1800's some of these flies began going to apples to mate and lay their eggs instead. These flies have now become genetically different from the flies that still visit the hawthorn fruit.

This is an example of how new species can form. Over time mutations, natural selection and other mechanisms of evolution affect the two fly population in different ways, until they are so genetically different they become species.


What is really interesting to me is how fast this happens, and that the same kind of speciation is also happening to the parasitic wasps that feed on the maggots of the flies. This is an example of co-evolution. Co-evolution happens when the evolution of one species affects the evolution of another.

So you see, it is not necessary to go off to some exotic place to study evolution. The process of evolution is happening all around us. Articles like this make me wonder what kind of evolution could be going on right here at the college?


Forbes et al. Sequential Sympatric Speciation Across Trophic Levels. Science, 6 February 2009: 776-779 DOI: 10.1126/science.1166981

Darwin Day Special: Discovery of new transitional fossil of whales announced

Boy oh boy, give me a little free time and look at all the posts I can publish! I'll leave the news about the giant fossil snake, Titanaboa cerrejonensis, for you to find on your own by the way.

Philip Gingerich and colleagues have just published an article describing fossils of whale ancestors they discovered in Pakistan. They found two adults, one male and one female, and as they uncovered the fossil of the female whale they discovered a fetus inside. These early whale ancestors still had legs, and most likely gave birth on land.

The fetus had teeth and was facing head first toward the birth canal which is why the researchers believe the animals gave birth on land. As you can imagine, heading into the water head first to take one’s first gulp of air would be disastrous for the baby. Modern whales are born tail first.

The well formed teeth suggest the young were very precocious, and ready to feed soon after birth.

The name of this 45 million year old ancestral whale fossil is Maiacetus inuus. You can read the article by Gingerich and colleagues here as well as see photos and drawings of the fossils.

Darwin Day Special: 635 Million year old Steroids

Scientists at the University of California at Riverside working with scientists at MIT have have discovered massive amounts of steroids in sediments that are 635 million years old. These steroids were made by sponges, and are the earliest evidence of animal life discovered to date!

You can read more about this discovery here

DNA a "bar code" for plants?

Last year researchers from the Royal Botanical Gardens in England in collaboration with researchers at the University of Johannesburg and the University of Costa Rica, discovered a gene that could be used to readily identify plant specimens. This gene called the matK gene is different in different plant species, but has the same DNA sequence in plants of the same species.

This gene could be useful to identify different plant species which look very similar, or to identify plants which have been pulverized for use in medicines or teas.

The use of this gene will also make it possible to identify endangered plant specimens more easily, especially those which physically resemble less rare plants. It could also be used for example, by customs agents trying to detect the illegal importation of rare or endangered plants from other countries.

To read more about this discovery click here

Bio 120 review questions for the first exam

Hi Folks,
These questions appear elsewhere on the blog, but I have brought them up in a current post so they are easy to find.

1. What are the building blocks of carbohydrates?
2. What is the difference between a saturated and unsaturated fatty acid?
3. Why is the shape of an enzyme important to the function of the enzyme?
4. At what level of complexity do proteins usually become functional?
5. What makes up a nucleotide?
6. What bond forms between amino acids as they react to form proteins?
7. How is the function of carbohydrates different in plants and animals?
8. What is the name of the carbohydrate human cells use to store glucose?
9. Which of the macromolecules we discussed stores energy in the most efficient way?
10. What is the most common steroid in the body?


Here's some more questions for you to answer !
1. A cell must maintain an imbalance of sodium ions on either side of the membrane for it to function. What process would it most likely use of the ones we discussed today in class?
2. How are polar and non polar covalent bonds different?
3. What is a hydrogen bond, and why are these bonds important to life?
4. Oxygen has 8 electrons, with 6 in the outermost energy leve. Will this atom react?
5. How are ions formed?
6. A solution with a pH of 5 is how many times more acidic than a solution with a pH of 7?
7. What determines if an atom with react with another?
8. A plant cell in a hypertonic solution will under go _____________
9. An animal cell in a hypotonic solution may undergo _____________
10. A Paramecium can survive in fresh water without bursting. Why?


1. How are the mitochondria and chloroplasts similar?
2. Why do we think the mitochondria was once an independent organism?
3. Describe the plasma membrane. Include how a lipid membrane functions in a watery environment.
4. What role do the proteins in the plasma membrane play?
5. How is active transport different from diffusion and osmosis, and faciliated diffusion?
6. How is dialysis different from osmosis?
7. What affect would a hypertonic solution have on a cell?


How is a hypothesis different from a theory?
What are five characteristics of living things?
How are prokaryotic cells different from eukaryotics cells?
What can cyanobacteria do that the bacteria living in your mouth do not do?
How are archebacteria different from the bacteria living on your skin?
Describe briefly what organelles would be involved in making a protein and exporting it from the cell.
Give an example of two cell organelles working together to accomplish a task.
What organelle is found on the ER?
What is the function of lysosomes?
Where is the nucleolus?
What are the functions of the Golgi bodies?

Of the taxonomic groups listed below, which is the least inclusive group?
domain, species, family, genus

To which Kingdom do you belong?

David Attenborough and the Tree of Life

Another preview about the Tree of Life. This is a wonderful representation of the Tree of Life on Earth. It is a beautiful presentation, even if it does seem to leave out plants. Algae at least get a brief mention. Take a look!

David Attenborough's new program: Darwin and the Tree of Life--

My favorite natural historian, Sir David Attenborough has developed a new program about Darwin and evolution. I am not sure when it will be broadcast, but I imagine it will be ready by the 200th anniversary of Darwin's birth which is Feb. 12.
Take a look at this short interview of Sir David for a preview of the coming show.

Endangered Species Around Us...

Belding's savannah sparrow , Bolsa Chica Ecological Reserve

This is the first in an occasional series about endangered species in Southern California.

Those of you in my classes have an opportunity to earn extra credit by working at Bolsa Chica to help restore the Bolsa Chica Mesa with native plants. One of the reasons Bolsa Chica is an important area is that it is home to a variety of threatened or endangered species. A threatened species is one that is likely to become endangered in the near future, and an endangered species is one that is in danger of extinction throughout all or most of its range.

Common reasons for species becoming endangered include habitat loss, pollution, or over hunting or fishing. Habitat loss is what caused the Belding's savannah sparrow (Passerculus sandwichensis beldingi) pictured above to be placed on the endangered species list. This bird lives all year at Bolsa Chica in and around a plant called pickleweed. Pickleweed grows in salt water wetlands or estuaries. We have lost over 95 % of our coastal wetlands in California to development. This loss of habitat has pushed this small bird to the brink of extinction.

Preservation of remaining coastal wetlands is important for the recovery of this and other species.

The 44th President

I am so happy to have a President once again about whom I can feel proud. His acceptance speech was moving, hopeful, yet realistic about the challenges we face. He even mentioned restoring science to it's rightful place in his administration. How about that- a President who believe science is important. Yeah! So what do you think?

I've been Obamaized, and so can you!

Just click here

Have you spent any time in community service today? Our soon to be President Obama, has called for us to remember Dr. Martin Luther King Jr. by participating in community service. Many of my students participated in the Bolsa Chica Stewards work day on Saturday. We weeded, watered and planted native grass and wildflower seeds on the Bolsa Chica Mesa. With the help of volunteers, the Bolsa Chica Stewards have planted over 15,000 native plants on the mesa as part of a project to restore the area to its native Costal Sage Scrub plant community.

Baja Coyote

My friend in Baja leaves water out for the birds, and the coyotes have also discovered it. Early in the morning this female appeared, as she slowly made her way up out of the arroyo.

She was very cautious, but finally came up toward the water.