Podcast Beta
Questions and Answers
Evolution is a temporary change in a species due to environmental conditions.
False
Natural selection includes the concept of survival of the fittest.
True
Darwin's observations aboard The HMS Beagle began in 1858.
False
Overbreeding leads to a decrease in population numbers.
Signup and view all the answers
The evolution of the horse indicates it has only increased in size over 60 million years.
Signup and view all the answers
The mechanism of evolution was first proposed by Charles Darwin and Alfred Wallace in the 1800s.
Signup and view all the answers
All individuals within a species exhibit identical traits.
Signup and view all the answers
Evidence for evolution can be completely proven beyond doubt.
Signup and view all the answers
Study Notes
Evolution
- An inheritable change in a species in response to a change in the environment by natural selection over a long period of time.
Theory of Natural Selection
- Proposed in 1858 by Charles Darwin and Alfred Russel Wallace.
- Published in the book ‘On the Origin of Species by means of Natural Selection’ in 1859.
Observations
- More offspring are produced than the environment can support.
- Population numbers stay the same.
- Inherited variations occur in populations (no two members are identical except identical twins).
Conclusions
- Struggle for existence: Overbreeding leads to competition for survival.
-
Survival of the fittest: Individuals with favorable variations are better adapted to the environment and have a better chance of survival.
- Examples:
- Deer that run faster can escape predators.
- Rabbits with improved hearing can hear predators and survive.
- Examples:
- Origin of species: Over time, the accumulation of advantageous variations results in offspring that are widely divergent from their original type. They no longer interbreed and form a new species.
Evidence for Evolution
Horse Evolution Example
- 60 million years ago: 0.4 m tall (size of a fox)
- 30 million years ago: 0.6m high (German shepherd height)
- 10 million years ago: 1m high (Great Dane)
- 1 million years ago (Equus, modern horse): 1.6m tall
Key Changes In Horse Evolution
- Increase in size
- Reduction in toes from four to one
- Change in molar teeth from low-crowned for eating soft foliage to hard ridges for chewing grass
Fossil Record Limitations
- Fossils are only found for the harder structures of plants and animals.
- Older fossils are difficult to date.
- Many fossils will never be discovered.
- Many fossils are destroyed by erosion.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge on the principles of evolution and the theory of natural selection as proposed by Charles Darwin and Alfred Russel Wallace. Explore concepts such as inherited variations, struggle for existence, and survival of the fittest. This quiz covers key observations and conclusions drawn from the theory.
