*Darwins evolutionary theory

Question 0

define fixity of species

Answer 0

The notion that a species, once created, can never change;
-This belief is generally not accepted by the majority in present times because of the vast amount of evidence supporting evolution.

Question 1

What was the name of the man who also came to the same conclusion about natural selection at the same time as Darwin?

Answer 1

Alfred Russel Wallace

Question 2

Explain Jean Baptist Lamarck’s theory: Inheritance of acquired characteristics

Answer 2

• If the external environment changed, an animal’s activity patterns would also change to accommodate the new circumstances. This modification would make the animal better suited to its habitat
• this would result in the increased/decreased use of certain body parts; those body parts would be modified

Question 3

Define reproductive success

Answer 3

The number of offspring an individual produces and rears to reproductive age; an individual’s genetic contribution to the next generation.

Question 4

Darwin’s basic processes

Answer 4

1) All species are capable of producing offspring at a faster rate than food supplies increase
2) There is a biological variation within species
3) In each generation more offspring are produced that survive, and because of limited resources, there is competition among individuals
4) Individuals who possess favourable variations or traits have an advantage over those who don’t have greater “fitness”
5) The environmental context determines whether or not a trait is beneficial. What is favorable in one setting may be a liability in another.
6) Traits are inherited and passed on to the next generation. over time those favourable traits become more common in the population. Less favourable characteristics are weeded out.
7) Over long periods of time, successful variations accumulate in a population, so that later generations may be distinct from ancestral ones. Thus, in time, a new species may appear.

8) Geographical isolation also contributes to the formation of the new species. As populations of a species become geographically isolated from one another they begin to adapt to different environments. Over time, as populations continue to respond to different selective pressures they may become distinct species.
ex) The 13 species of Galapagos finches

Question 5

Define Selective Pressures

Answer 5

Forces in the environment that influence reproductive success in individuals.