Darwin and his theory of evolution

what's evolution

explains that what we see today is different from what existed in the past

Galaxies, stars, the solar system, and earth have changed through time, and so has life on earth.

It explains that living things share common ancestors.

Darwin called this process "descent with modification," and it remains a good definition of biological evolution today

darwin's misunderstandings

Evolution is a “ladder of progress”, a steady march of progress with organisms constantly getting better

Evolutionary theory is a theory about the origin of life.

fossil record is not complete shows evolutionary theory to be false

Because evolution is not observable or testable it is not science.

Evolution and religion are incompatible

Responses to his misunderstandings

Natural selection does weed out individuals unfit for a particular environment but conditions are changing

The origin of life is not the main focus of evolutionary theory but rather the way life changes after its origin

Fossilization is a very rare event. There must be specific conditions for a creature to be fossilized

Evolution is both observable and testable

the fossil record

Study of living species e.g. Darwin’s Finches

A rtificial selection in the laboratory

genetic mutation e.g. in fruit flies

in the scientific community there are thousands of scientists who are devoutly religious and also accept evolution

the importance of his voyage to galpage islands

he noticed different finches which helped him to develop his propositions

Darwin's propositions

Artificial selection has a marked effect on the domesticated plants and animals, although it is applied for a small number of generations

if a change occurs in the physical environment, individuals will be exposed to new circumstancesso individuals'll try to adapt

All species are characterised by variation between individuals

this will urge the tendency for varieties to be distinct successive generations

This PRINCIPLE OF DIVERGENCE is the most important factor in the evolution of new species

Species arose by COMMON DESCENT, as a result of DIVERGENCE from a COMMON STOCK

NATURAL SELECTION was the process by which new species were brought into existence

Darwin's book (the origin of species by natural selection)

there are differences betwwen offspring that survive and reproduce and those who don't

those who have heritable characteristics enable them to survive and pass those characteristics to their offspring

natural selection of varients explaned observations on the geography of species differences

what's the ultimate source of variations

mendal shows that organisims acquire traits through discrte units of heridity which later(genes)

the variations produced in these inherited traits is the raw material on which natural selection acts

evolution was seen to depend on genetic mutation and naturl selection