Bio 15 Flashcards
evolution
The cnage in a population over time
theory
well supported testable explanation for a natural occurance
evolutionary theory
Facts, observations, and theories about how different organisms and species evolved.
fossil
bones/ parts of a body that have been preserved over time
Charles Darwin
English scientist with a degree in theology who traveled the world on the beagle and collected evidence to support his evolutionary theory
natural selection
process by which organisms well suited (or fit) to an environment survive longer and reproduce more than those who aren’t
How did Darwin collect evidence on his voyage
He collected different specimen and ate many of them, he also collected fossils
What did Darwin notice on the Galapagos islands
He noticed that they each had different climates and very slightly different species–
-different finch beaks, different tortoise shells
Does life change over time?
YES!
life often adapts to its enviornment
Descent with modification
Darwin theorized that all species descended with modification from one ancestor- THIS WAS THE PRINCIPLE OF COMMON DECSENT
Which two people influenced how darwin thought the earth had geographically changed? HOW?
James Hutton- layers of rocks are pushed up and around very slowly, earth must be old
Charles Lyell- processes that shaped earth millions of years ago still shape it today.
Who was Lamarck
He was the first scientist to suggest life changes over time, he was wrong in some places but still had a revolutionary idea
What were Lamarck’s evolutionary hypothesis
- organisms acquire traits helping them towards perfection
- Organisms only keep traits they use
- Acquired traits are inherited
What was wrong about Lamarcks Evolutionary hypothesis
Organisms don’t “acquire traits”, mutations cause changes in genetic makeup and changes in traits
How did Thomas Malthus’s work on population growth impact Darwin and his views of the world
Thomas Malthus stated that the human population was out growing earths resources:
- Darwin realized that most populations must compete for food in a “survival of the fittest” sort of way.
Adaptation And Fitness
Adaptation- inherited gene that becomes more common because the trait increases an organism’s fitness
Fitness- ability to SURVIVE and REPRODUCE
Alfred Russel Wallace
Darwins “pen-pal” who had similar hypothesis about evolution and helped darwin to want to publish his book, “On the Origin of Species”
Artificial selection
When humans select certain traits they find useful as breeders/ farmers/ etc.
Natural variation and Inherited variation
The genes of every organism in a population have a bit of variation and that allows for artificial and natural selection to occur.
struggle for existence
Every single organism struggles for existence and the best fit to compete for resources survives and reproduces
THIS IS ALSO NATURAL SELECTION
What does differential reproductive success mean?
every organism has a different chance of being successful in terms of SURVIVING and REPRODUCING, this is a measure of FITNESS
(T or F) Most of the species on earth have come and gone without a trace
TRUE
What are some of the key pieces of evidence for evolution?
- The fossil record
- Geographic distribution of living species
- similarities in fetal development
- similarity in genetic material
How does the fossil record help darwin prove evolution
The fossils provide evidence of past life that was on earth and links to current species
How does the geographic distribution help darwin prove evolution
- different species in SIMILAR geographic locations with similar features both developed those adaptations
- SAME species in DIFFERENT geographic locations with different features seperated and developed different adaptations.
How does early fetal developement help darwin prove evolution
- many animals have similar fetuses and share vestigial and homologous structures
vestigal vs. homologous structure
vestigial structures are often very similar in different organisms, they often preform no specific function like a hind limb in whales that has no use. Homologous structures have common ancestory and develop differently so that the organism can better use it.
How did DNA help scientists prove evolution
by looking at DNA of different species scientists can notice similarities and differences and can see which ones MOST RECENTLY SHARED A COMMON ANCESTOR
What are three Evolutionary examples
- Bacteria of tuberculosis developed immunity to antibiotics due to a mutation
- Finches beaks get long and large beaks during dry season, they have small beaks during wetter years
- Moths with darker colors were more common during the industrial revolution because they couldn’t be seen as well
gradualism vs. Punctuated Equilibrium
Gradualism- Darwin believed most species evolved slowly and gradually
Punctuated Equilibrium- MOST COMMONLY species develop over sudden changes and periods of time without change.
