darwin presents his idea
Post on 22-Feb-2016
77 Views
Preview:
DESCRIPTION
TRANSCRIPT
DARWIN PRESENTS HIS IDEA
By: Sandy Gomez
Darwin presents his idea
Gathered data aboard the Beagle
Made important observations and conclusions
Linked his idea with other scientists findings
Trying to explain what other scientist
couldn’t: EVOLUTION
Darwin’s Reasoning
Plants or animals that arrived to Galapagos Island faced conditions that were different form those on mainland.
He hypothesized that organisms gradually changed over many generations and became better adapted to the new conditions.
Darwin presents his idea
Natural Selection:
Process by which, individuals who are
better adapted to the environment are
more likely to survive and reproduce than
other members of the same species.
Led to evolution, but how?
Natural Selection
1. There is variation in traits. For example, some beetles are green and some are brown
Natural Selection2. There is differential reproduction.Since the environment can't support unlimited population growth, not all individuals get to reproduce to their full potential. In this example, green beetles tend to get eaten by birds and survive to reproduce less often than brown beetles do
Natural Selection
3. There is heredity.The surviving brown beetles have brown baby beetles because this trait has a genetic basis.
Natural Selection4. End result:The more advantageous trait, brown coloration, which allows the beetle to have more offspring, becomes more common in the population. If this process continues, eventually, all individuals in the population will be brown.
Factors That Affect Natural Selection
Overproduction of the offspring Variation within species
Factors That Affect Natural Selection
Variations are inherited
Factors That Affect Natural Selection
Isolation
EVIDENCE OF EVOLUTION
Evidence of Evolution Fossils
Evidence of Evolution
Fossils
Saber Tooth Tiger
Evidence of Evolution Embriology
Evidence of Evolution Homologous Structures
Evidence of Evolution Analogous Structures
Evidence of Evolution Vestigial Structures
Evidence of Evolution Vestigial Structures
Evidence of Evolution Vestigial Structures
Important questions to answer
What is natural selection? Which are the conditions needed for
natural selection to occur? Describe each one and give an example.
Which are the main pieces of evidence that might prove evolution? Describe each one.
Why is each piece of evidence said to be it?
top related