College Biology - Evolution Videos

What is evolution?

The development of life on earth

Change in gene pool over time

What has evolution provided our earth with?

Variety

What was the “first” organism that all organisms came from?

Protist

What is a species?

Community of organisms that can mate and have offspring

What makes each human different?

All have slightly different traits and characteristics/slightly different DNA in each

What carries the information of life?

Genes in DNA contain instructions and traits

Why is it important that most species produce an excess production of offspring?

The more offspring produced, the more little differences occur. Nature wants as many little differences as possible

What is “heredity”?

Passing on of DNA to offspring

What is a “mutation”?

Random changes in DNA

What is “recombination”?

Random mixing of DNA (meiosis-sperm and egg/making child)

Give an example of a negative mutation.

Cancer/toxins = chemical or radiation

Give an example of a positive mutation.

Blue eye color in humans

In the heredity process →creatures pass on their characteristics to offspring via ____→____ and ____ change the DNA and→ each child looks different from parents because

DNA; recombination; mutation; different combination of sperm and egg

All variations are based on ___.

Chance

What is Natural Selection?

Survival of Fittest

Survival of Fittest

Most appropriate DNA for that environment makes them fit = can reproduce

What are some “environmental influences” that each have an effect on a species?

Predators, toxins, parasites, climate, changes in habitat

How does their DNA help them survive/not survive in their environment and exposure to such influences?

Those with the right DNA mix give them survival and change to reproduce

If you are a “fit” individual, according to biology and natural selection, what do you get to do?

Reproduce

How did Natural Selection cause a change in the finches of the Galapagos Islands?

Different food sources were chosen due to different beak sizes (small beaks = worms/big beaks = seeds)

Over many generations, they could no longer mate (new species) = made “niche”

What does the pinky finger represent in the 5 processes that can cause evolution?

Small population

What does the ring finger represent in the 5 processes that can cause evolution?

Non-random mating - choose mate based on appearance

What does the middle finger represent in the 5 processes that can cause evolution?

Mutation

What does the point finger represent in the 5 processes that can cause evolution?

Gene flow - movement in or out

What does the thumb represent in the 5 processes that can cause evolution?

Natural Selection = adaptations

How does microevolution lead to macroevolution?

Speciation = small changes in the gene pool lead to changes in the population on a large scale

What are evolution’s 2 claims?

All living things on Earth are related

Evolution is powered by natural (processes) selection

What are cetaceans?

Whales, dolphins, propoises

What do scientists think cetaceans evolved from?

4-legged land mammal

List the evidences of evolution.

1. Comparative Anatomy

2. Embryology

3. Fossil Record

4. DNA Comparison

5. Species Distribution

How is a whale/dolphin bone (anatomy) structure similar to that of a human?

Blowhole in skull splits into 2 nasal passages (highly modified mammal nose)

How is a whale’s embryology similar to that of a human?

Both have tails

How does the fossil of a Basilosaurid Whale show evolution? Give 2 examples.

Mammals - nose at tip of snout

Basilosaurid - nostril in middle

Dolphin/Whales - nose on top of head

This shows there was an intermediate species

According to a whale’s DNA, what “water animal” is it most closely related to?

Hippopotamus

Where did birds evolve from?

Dinosaurlike ancestors

Bird wings = modified claws

Where did mammals evolve from?

Reptile-like creatures

Fish-amphibian-reptile-bird/mammal

What are the steps to evolution?

Natural Selection→Adaptations (Mutation) → Population Change →Evolution

What does fitness mean?

Those that can reproduce; they are not biggest

What was the end result of Natural Selection in the finches?

14 different species

What percent of all species are extinct?

99%

In comparison to today’s world, what percent of history was completely different from humans?

99.99%

What happened 2.8 million years ago?

The genus “Homo” (humans) emerged

Who was Homo Erectus?

Another human species that was ten times larger than modern humans; survived for 2 million years

What event caused humans to evolve? How did it help change humans?

Learned to control fire = scared predators and used for hunting and warmth

Allowed for cooking (more nutrients)

The food meant greater brain development

What “event” changed the process of human evolution?

Agricultural Revolution (12,000 years ago)

What “event” laid the foundation of the modern world?

Industrial Revolution (1st century - appx. 2,500 years ago)

What is the hierarchy of classification of humans?

Animalia Chordata Mammalia Primates Hominidae Homo Sapien