RSS

Tag Archives: darwin

Evolution Animated

I just stumbled upon this cartoon for the first time today and I’m totally blown away. Sure, there are some things that could be explained better. There are a couple of moments when the illustrations could be a bit more accurate. But, overall, it’s a very good summary of the basic elements of evolution and pretty funny. (I wish I had made this!)

Have a watch and enjoy.

also, check out Kurzgesagt’s other animations on the Big Bang Theory, et al.

 
Leave a comment

Posted by on March 6, 2014 in Uncategorized

 

Tags: , , , , , , ,

The Question of Death

Image

Death’s Dance

In the film, Questioning Darwin, it is asked of ‘Darwinists’, “How does evolution deal with death?”

I have to admit, I don’t know what this question really means.  Is he asking why there is death? What happens after death?

Several people texted just this question during the live broadcast of the Nye / Ham debate and I didn’t understand it then either. In that context, they had posed this question as something of an experimental challenge to evolutionists and I interpreted it as meaning … ‘ Just wait until you die, heretic. Then you’ll see who’s right.’ Perhaps I had been to quick to this conclusion ?

If there is anyone out there who can explain just what this means, please let me know. Right now it’s nothing but an inside joke that I don’t get.

 
3 Comments

Posted by on February 24, 2014 in Uncategorized

 

Tags: , , , , , , , , , , ,

Darwin Day

ImageToday, February 12, 2014 is Charles Darwin’s 205th Birthday – unofficially recognized as Darwin Day, a day to consider what science and medicine have achieved since the publication of Darwin’s Origin of the Species. For suggestions on how you can celebrate / honor / enjoy this day, see the list below, which I have taken from the Darwin Day Challenge Scavenger Hunt. The scavenger hunt was originally meant to be tackled as a 30 day exercise ending today, but since today is the last day, just pick one from the list.

Darwin Scavenger Challenge 2014

  1. Reacquaint yourself with the classification of plants and animals: kingdom, phylum, class, order, family, genus, species.  (You can use Wikipedia or the kid-friendly link above.)
  2. Read a book about Charles Darwin to yourself or family members. (ex. Tree of Life by Peter Sis, One beetle too many : the extraordinary adventures of Charles Darwin)
  3. Draw a picture of yourself with a beard like Charles Darwin or make one and take a picture of you wearing it. (I would love to see pets wearing it too.)
  4. Watch a movie or show that features Charles Darwin. (BrainPop What Darwin Didn’t Know,  Creation,Master and Commander)
  5. Create your own Phylum Feast – a meal with as much biological diversity as possible.  Or just label all dishes in your meal by their main ingredients’ scientific names.
  6. Visit a Science Institution. (in SoCal: California Science Center , Discovery CenterNatural History Museum).
  7. Visit a zoo, farm or animal sanctuary and observe characteristics and/or adaptations of species from the same continent (in LA county LA ZooGibbon SanctuaryUnderwood FarmsGentle Barn).
  8. Design, draw or create a life form of the future.  Consider what might truly exist in 1,000 years based on the future changes of our planet.  Or just let your imagination go inter-planetary.  We will quite possibly know more neighbors in the next millenia.
  9. Habitat Hike – Take a hike in nature and observe it as a habitat.  What are some possible food chains in that environment? What types of homes have the animals and insects created?  Can you identify examples of all five Kingdoms on your walk? How many different species of one animal can you count?
  10. Recreate a habitat out of anything you want: legos, art supplies, minecraft, cheese, etc.
  11. Do something to help protect or clean up your world.  The sky is the limit.
  12. Attend any naturalist event.  Ranger-led or docent-led hikes, a nature talk (Santa Monica Mts Events), a biology lecture, etc.
  13. Make 3 lists of adaptations. One each for an animal, bug and plant of your choosing.
  14. Set up a debate on any topic with your family and/or friends (it does not have to be evolution vs creation).  This is to celebrate our investment in rational thought!
  15. Visit an institution involved with Astronomy or the Sciences of the Sky.  (Griffith observatory or any LA-area planetarium .
  16. Draw the night sky anyway you wish to depict it.
  17. Sit outside anywhere and spend 5 minutes with your eyes closed listening to as much life as you can detect (if you fall asleep you will have to start all over).  Spend an additional 5 minutes counting the evidence of biological diversity of life. Leaves rustling- 1; bird chirping-2; crow caws -3; car starting – 4; children wiggling – 5; bicycle in park -6; insect snapping-7.
  18. Visit any body of water and witness the life there (or absence of life).  Beach, pond, river, creek, even a puddle counts.
  19. Spend 3 consecutive hours using ONLY the items that existed during Darwin’s life 1809-1882.  No cellphones, no microwaves, no cars, no tvs, no computers, no refrigerators, no light switches (invented in 1884 by John Henry Holmes). Bonus point if you can go a whole day.  Doing this while you sleep will not count.
  20. Observe a sunset.
  21. Observe a sunrise.
  22. Touch a fossil.  Darwin was fascinated by fossils, since so many that were unearthed during his time were not a perfect match to the animals alive.  He felt the fossil records of his time were not complete enough to prove his theories.
  23. Learn 5 facts about one animal or bird that is extinct.
  24. Learn 5 facts about an animal or bird on the endangered species list including how many are left on the planet.  Example – 150 Kakapo’s left.
  25. Find out which threatened species lives closest to your home.
  26. Attend a cultural event or festival to better understand the diversity of your species. (A few SoCal fests: theLunar New Year Fest (1/18), and LA’s Chinatown New Year’s Parade (2/1) and Vietnamese Tet(2/7,8&9).
  27. Imagine your life if you were a different race, sex, neuraltype, sexual orientation, or nationality (or all of them).
  28. Build a monument outdoors to Science (temporary, permanent, or whatever).  Take a picture and send it to me if you can.
  29. Read some pages outloud of any of Darwin’s books.  Origin of Species is the most famous.

GodMakesTheSnakeCartoon

 
Leave a comment

Posted by on February 12, 2014 in Uncategorized

 

Tags: , , , , ,

Visit my Ted Ed flip of the lesson: Myths and Misconceptions about Evolution

ImageTake a look at my new flip of this lesson on Ted Ed:

Myths and Misconceptions about Evolution

http://ed.ted.com/on/HQPBkX36

Then come back here and leave your feedback about what the lesson includes and what you learned or did not learn about. I’d love your feedback on the associated questions and discussion topics so I can edit and optimize them before I show it to my class in the Fall.

 
1 Comment

Posted by on July 8, 2013 in Uncategorized

 

Tags: , , , , , , , ,

The House Where Darwin Lived

ImageLike a barnacle, Darwin settled into his home not far from Kent, England that is featured in last month’s Smithsonian Magazine.

I have this spot on my science bucket list along with Galapagos, Brno and others.

 
Leave a comment

Posted by on February 24, 2013 in Uncategorized

 

Tags: , , , , ,

Refining the Tree of Life

Image“Therefore I should infer from analogy that probably all the organic beings which have ever lived on this earth have descended from some one primordial form, into which life was first breathed.”

Darwin, Origin of the Species 

One of the basic ideas of biology is Darwin’s notion that all life on this planet is related through common ancestors at some time. It is only though the passage of ‘deep’ time, the infidelity of genetic machinery (among other processes) leading to variation and the separation of species by physical (or other) boundaries that has led to divergence into the great variety of species we see today. Constructing phylogenetic trees is a simple graphical way of communicating this concept.

The Animal Tree of Life, published in the 15 Feb 2013 Science magazine <LINK>discusses the construction of a phylogenetic tree over the past 25 years since molecular evidence was admitted as a means of establishing relationships with greater accuracy, and with less subjectivity than ever before. “  For the past century, the use of detailed descriptions of animal adult morphology and embryology has been at the heart of the study of evolutionary relationships among distant groups such as phyla. However the methodology can have both implicit problems and practical difficulties.”    1

This early paper used 18S rRNA sequences extensively to derive phylogenies because it was thought that this gene was required for life of many (all?) organisms and that sequence was highly critical to an organism’s survival, and would suffer fewer modifications over time than other, less crucial genes.

The earlier disagreements derived from varying interpretations of the morphological and embryological characteristics of animals. Many of these characters have evolved repeatedly in unrelated lineages as adaptations to similar selective pressures or have been lost from certain groups through disuse. Today’s strengthening consensus is almost entirely thanks to the use of molecular genetic data in reconstructing trees. Heritable changes in nucleotides and amino acids are abundant and generally much less prone to the problems of convergent evolution and loss than are morphological characters.2

Image

More recently, sequencing of mitochondrial and chloroplast DNA has revealed these organelles’ relationship to free-living bacteria, providing an interesting challenge for illustrators of these genetic trees and establishing solid data supporting the endosymbiotic theory.

Using the great wealth of DNA data we have today, relationships can be determined using similarities found in a number of different genes, providing a high degree of statistical assurance that the conclusions are unbiased and accurate.

Image

References

1. K. G. Fieldet al., Science 239, 748 (1988).

2. M. J. Telford, R. R. Copley, Trends Genet. 27, 186 (2011).

 
Leave a comment

Posted by on February 19, 2013 in Uncategorized

 

Tags: , , , , , , , ,

Is Saudi Arabia following Turkey’s Lead?

MukfellasIt’s unclear what the rationale was, but The Economist has recently reported that the Saudi Arabian Committee for the Promotion of Virtue and Prevention of Vice (CPVPV) has come in and closed the Dinosaur World exhibit / playground. I’ve looked around a bit to see if there is any further information explaining this action (is it a reaction to the very idea that once dinosaurs roamed the earth?, perhaps some incidents of improper behavior had been reported?). In the absence of information, we can only guess.

I was alerted to this news via a blog that I follow by the evolutionary biologist, Jerry Coyne. Coyne’s interest comes from his concern about the suppression of science that is sometimes found amongst religious organizations. Because this action was carried out by the CPVPV, it is reasonable to assume that the exhibit was closed because it violated a tenet of the islamic faith. The CPVPV is the Saudi religious police who enforce Sharia Law by monitoring the population to ensure that people adhere to dress codes, separation of men and women, etc.

t rex exhibition riyadhHowever, it’s difficult to look at pictures of this exhibit and see what could be wrong. Although he does not say it explicitly, I have a feeling that Coyne is worried that Saudi Arabia is going the way of Turkey in suppressing science that contradicts religious interpretations of creation. This is an issue in many Christian-dominated cultures, but many people do not realize that fundamentalists of Islam are very similar in their views as fundamentalist Christians. Read more about recent actions prohibiting teaching of evolution in Turkey here.

 
Leave a comment

Posted by on January 22, 2013 in Uncategorized

 

Tags: , , , , , , , ,

What kind of planet do we live on?

This is the last week of my Fall 2012 General Biology class and we have finally gotten to the material I look forward to all year.

Throughout the semester we build towards an understanding of the central dogma (DNA –> RNA –> Protein). Early on we are introduced to this idea and are given the basics that DNA is the information that is required to build cells; which are made of these proteins as well as some other biomolecules. It’s easy to have a protein-centric view of the cell because these molecules provide structure to the cell and accomplish many of the functions of the cell by acting as receptors, enzymes, signaling molecules, etc. (This is an over-simplification, but one I can live with)

Last week we focused on the details of transcription and translation and how these molecular processes read information from DNA to make an mRNA ‘message’ that leaves the nucleus and goes to the cytoplasm where translation of this message results in the production of a protein with the specified amino acid (AA) sequence.

This segued into what happens when there are errors or mutations along the way. Because the AA sequence of the protein is determined directly from what is encoded in the DNA, changes is DNA may have direct consequences on the protein. Another central idea I teach is ‘Form Dictates Function.’ Because the form of a protein is determined by the AA sequence, changes in sequence mean changes in form and therefore changes in function.

So, how does this relate to my opening question, ‘What kind of planet do we live on?’

A Molecular View of The Central Dogma

A Molecular View of The Central Dogma

The process illustrated by the central dogma is fairly faithful. Most often the proteins are NOT mutated and are made just as the DNA directs and they function as expected. However, once in a while, mutations come in and hit the DNA and there is suddenly a DNA change leads to a change in the RNA, that leads to a change in the AA sequence, that leads to a new folding of the protein. This may provide a benefit (very rarely) or may cause a problem (more commonly). If it confers a benefit, this provides an advantage to the bearer of these new proteins and they may be more successful living longer and leaving more children. If it is detrimental, then the bearer may not live as long and may have few, if any, children.

But this is a SLOW process.

If the world was 4000 years old, this process could not conceivably explain the diversity of life on Earth. But if the world is 4.5 BILLION years old, that may be enough time. Darwin struggled with this idea and it was not until he witnessed the wide world during his voyage aboard the HMS Beagle that he started to see evidence that the world was much older than he once suspected.

Andean Fossils

Marine Fossils from the Andean Mountains – Similar to what Darwin found in the same place.

One of the first suggestions that Darwin say about the history of the Earth was the presence of sea fossils high in the Andes Mountains. How could this be? These could only make sense if the mountains were not always mountains, but the Earth changed over time.

With the idea of ‘deep time’, meaning that the Earth is very, very old – on the order of Billions of years – Darwin’s idea of mutations accumulating over time as fuel for evolution becomes plausible.

What kind of planet do we live on?

A very old , changing planet

 
Leave a comment

Posted by on December 4, 2012 in Uncategorized

 

Tags: , , , , , , , ,