Please enable JavaScript.
Coggle requires JavaScript to display documents.
Evolution:, Evolution happens because of genetic differences between…
-
-
Variations arise because genes from parents are combined and also due to spontaneous mutations in genes.
Minor differences between individuals don't matter much when things are going well, but when life is hard those individuals who possess characteristics that help them to stay alive and reproduce are the ones who pass their genes onto the next generation.
Individuals who cannot survive or fail to reproduce are not resent represented in future generations.
Reproduction is key - if an individual doesn't reproduce successfully the characteristics are not passed on.
After many generations of small differences, there are individuals who are different from their predecessors, the process by which is occurs is natural selection- the choosing, done by the environment, of individuals who can survive and reproduce successfully.
This idea proposed by Charles Darwin in 1859 is often called the ‘survival of the fittest’. Fit in this context refers to the characteristics that best match the demands of their environment.
Natural selection, although Darwin didn't know it, is due to their survival of genes. Natural selection happens when there is competition for scarce resources (including reproductive mates).
The genes which are most useful are retained in the population on overtime become more frequent. The outcome of selection is adapted, and the average survivors are better suited to life in the current environment than the average predecessors.
-
It explains why some characteristics that might appear disadvantageous actually confer a survival advantage because they can use it to attract potential mates.
Behaviour characteristics are adaptive because they provide an advantage of reproduction competition.
e.g: Aggression in males.
-
-
-
-
-
-
Steiner (2016) - points out that protecting offspring is one situation in which females will act as aggressive as males.