Evolution

Evolution

The process of change over time

Fossil Record

Shows how things have changed over time through looking at all known fossils

A fossil is remains of an organism that have been preserved

Fossil records often show proof of speciation, or the formation of new species. Looking at fossils of different species and being able to date them helps scientists figure out how species evolved.

In the Australian outback a fossil was found of a fish giving birth! The fossil is about 375-380 million years old and it shows the mother fish and the baby fish connected by an umbilical cord. Not only is this the oldest evidence of a vertebrea giving birth to live young, but it's of a fish- a creature which pressently doesn't give live birth. This is a record to show how fish have evolved over time.

Whale Fossil

Fossil records of whales show they have evolved drastically over time. Whales are believed to have been originally land animals that then evolved into ocean dwelling mammals. Scientists have been studying whale fossils to see this transformation in multiple parts of their body—one of which being their ears.

Around 50 million years ago, "whales" (whale ancestors specifically) were living on land, and fossils of those ancestors show the ears to be capable of hearing sound waves in the air.

In 43-46 million year old "whale" fossils, the ears had changed some. This ancestor of modern day whales was moving between land and water. It's ears had developed some of the modern-day-whale-ear characteristics, but not fully.

Fossils show that about 40 million years ago was when modern day whale ears started developing. These ears enable whales to hear underwater clearly, but sounds above ground do not come across as easily.

Comparative Anatomy

Shows how different organisms have similarities between parts of them which helps provide evidence for scientists to see if organisms may have shared a common ancestor

A homologous struture is a body part which different species have, but are simliar in structure and inherited from a common ancestor

Bats, whales, birds, dogs, humans and other animals have a forelimb that is very simliar. Theses forlimbs have simliar sturctures; they have the same number of bones, arranged in almost the same way.

Putting cute animals (not to mention a cute guy) in my project, and it actually fitting in?! Wow, I think that calls for some bonus points ;)

An analogous structure are body parts which have similiar functions to one another, but different structures

An example of one of these are the wings of a dragon fly and the wings of a bird. Both the dragon fly and the bird use these wings for the same function--flying, but the stuctures are highly different from each other. A bird's wings have bones and are covered in feathers, while dragon flies' wings have neither of those structures.

Vs.

A vestigial structure is a body part that doesn't have much of a use or function, but was inherited from an ancestor

Whales have a vestigial hind leg. This helps support the idea that they evolved from a land animal. They still have the leg, but it's useless to them, because, ya know... they live underwater... and swim... and it's really more of bones then an actual leg...

Humans have more then 100 vestigial structures in there body!!!

So 100 parts of you are useless or almost useless... Makes you feel special doesn't it?

Comparative Embryology

Shows how embryos from different species are similiar until they develop more fully

At the beginning embryo stages, humans, fish, bird, and rabbits all have gill slits, a two-chambered heart, and muscled tail. This is common in a wide variety of animals, giving proof to theory that these creatures evolved from a common ancestor.

When frog and mammal embryos are developing they both follow the holoblastic cleavage pattern (when the whole egg is divided into smaller cells). Even though these creatures go on to develop into very different specimens, these similar characteristics of embryology show that they developed from a common ancestor at one point of another.

Biogeography

Shows where the organsims live, and have lived and compares types of animals to the types of their environments

Almost all marsupials are found in Australia, but Australia is home to few placental animals. Scientists gather from this that animals were distributed to Australia and then they evolved from there, which is why they have this similarity.

The Arctic and the Antarctic have similar conditions, but different animals live at both. Penguins, for instance, live in the Antarctic

While polar bears and walrus live in the Arctic. Since the two places are on opposite ends of the Earth, the animals had to evolve from different species, and therefore evolved differently.

Molecule Biology

Shows evolution by studying organsims at a molecular level based on the molecules' structure and function and how that works in with their biological processes

Scientists have found that the closer the similarities between DNA, the closer the organisms are in the evolutionary tree. Humans and chimps have very similar DNA (99.99%) and are believed to be evolved very closely to one another. Chimps are said to be human’s closest living relative. Meanwhile, things with DNA that aren’t very close to each other, like slime molds and humans, aren’t close to each other evolutionary either.

All mammals except for humans, primates and guinea pigs have the enzyme LGGLO (which is why humans, primates and guinea pigs need vitamin C). Where did all of the mammals get it? I’m gonna place my bets on inheritance from a common ancestor. Like other body parts, molecules like enzymes can also be inherited into an organism, so when the organism evolves gradually the enzyme remains being passed on. Since primates and humans are said to be closely related to one another it is not too big of a surprise that this enzyme was not passed on to each of them, because it was probably a common ancestor that didn’t get it and therefore could not pass it on.

Observed Evolutionary Change

When people have directly observed the evolution

In a lab scientists saw how some of the bacteria, E. coli, evolved. Many bacteria can use citrate, E. coli was one of the species that never could—or so we thought. When scientists were running tests a mutation cause E. coli to be able to metabolize citrate. This group of E. coli was then able to increase more than the other groups in population size. These E. coli evolved because of a mutation, but they still evolved.

Evolution is often observed through natural selection or organisms surviving and producing more offspring because they are better suited for their local environment because of adaptations and fitness. An adaptation is a characteristic that can be inherited that helps an animal survive or reproduce. Fitness is how well an organism can survive and reproduce in their environment. Kind of redundant, right? Natural selection has been observed many, many times. One of those was a species of moths all living on a tree. The moths that were better camouflaged in that environment—the tree—were the ones that lived. They had a better adaptation for that particular environment and therefore greater fitness. In the end, there were only the good-camouflaged moths left on the tree because the others had been snatched by prey and couldn’t produce offspring. On the other hand, the ones with the good camouflaged survived because they had less of a chance of being eaten by prey and therefore could produce offspring to carry on their adaptation.

Rio Star grapefruit is quite delicious, but that’s not important (for this particular project). It wasn’t as delicious before it evolved though. Scientists exposed seeds to radiation and the seeds then evolved to create a new type of grapefruit. This evolution was man induced, but evolution is simply change over time, and Rio Star is an example of a fruit changing over time (even if it was a shorter period then what is normally thought of to be “evolution”).

Works Cited

"Actionbioscience | Evidence of Evolutionary Transitions." ActionBioscience - Promoting Bioscience Literacy. Web. 08 Jan. 2012. <http://www.actionbioscience.org/evolution/benton2.html>.

Annis, David. "Macro-evolution Observed in the Laboratory | Digital Bits Skeptic." Digital Bits Skeptic | Skepticism. Critical Thinking. Podcast. Community. Web. 08 Jan. 2012. <http://www.dbskeptic.com/2008/06/21/macro-evolution-observed-in-the-laboratory/>.

"Biogeography & Evolution - How Biogeography Supports Evolution." Agnosticism / Atheism - Skepticism & Atheism for Atheists & Agnostics. Web. 08 Jan. 2012. <http://atheism.about.com/od/evolutionexplained/a/BiogeographyEvolution.htm>.

"Biology: Evidence for Evolution." Get Homework Help with CliffsNotes Study Guides. Web. 08 Jan. 2012. <http://www.cliffsnotes.com/study_guide/Evidence-for-Evolution.topicArticleId-8741,articleId-8636.html>.

"Comparative Embryology - Developmental Biology - NCBI Bookshelf." Web. 08 Jan. 2012. <http://www.ncbi.nlm.nih.gov/books/NBK9974/>.

"Daily Kos: Major Evolution Observed in a Lab." Daily Kos :: News Community Action. Web. 08 Jan. 2012. <http://www.dailykos.com/story/2008/06/11/527201/-Major-evolution-observed-in-a-lab>.

"Definition of - Merriam-Webster's Student Dictionary." Merriam-Webster's Word Central. Web. 08 Jan. 2012. <http://www.wordcentral.com/cgi-bin/student?book=Student>.

"Evolution: Converging Lines of Evidence." Main Page. Web. 08 Jan. 2012. <http://www.freethoughtdebater.com/FEvolutionCase.htm>.

"Fossils Show How Whales Evolved to Hear Underwater." Daily Nature and Science News and Headlines | National Geographic News. Web. 08 Jan. 2012. <http://news.nationalgeographic.com/news/2004/08/0811_040811_whale_evolution_2.html>.

"Observing Evolution - How Evolution Has Been Observed." Agnosticism / Atheism - Skepticism & Atheism for Atheists & Agnostics. Web. 08 Jan. 2012. <http://atheism.about.com/od/evolutionexplained/a/ObservedEvolution.htm>.

"Oldest Live-Birth Fossil Found; Fish Had Umbilical Cord." Daily Nature and Science News and Headlines | National Geographic News. Web. 08 Jan. 2012. <http://news.nationalgeographic.com/news/2008/05/080528-mother-fossil.html>.

http://science.jrank.org/pages/348/Anatomy-Comparative.html

http://library.thinkquest.org/2869/evolve.htm

https://docs.google.com/viewer?a=v&q=cache:HmP9Gl3mcv0J:curriculum.bsd405.org/sites/Curriculum/Science/bio/WEB/evo/Lesson%252010/biogeography.doc+&hl=en&gl=us&pid=bl&srcid=ADGEESgf11yVp_X7jRPmvwf_AhEl6wgonnhzvhj10gDoDamq4OSrusHkDcCS6mGJ1dT913gH7lrihzZZ7kYeyd-pkFzzeZf8IMb7jtZihlFW5Oc5WwJWKmGvIVxDLfTW5xObAjAHAYHK&sig=AHIEtbSNBr6OZZh29GiMllbhKj4tfOb6ug

http://library.thinkquest.org/27407/fossil.html

http://library.thinkquest.org/27407/glossary/f.htm#fossil

AKA random, useless bones

When there is an analogous structure, scientists know that the organisms did not inherit these traits from a common ancestor.