Категории: Все - selection - adaptation - evolution - ancestors

по gigi moawad 17 лет назад

301

Darwin and his theory of evolution3

Charles Darwin introduced the theory of evolution, which explains the diversity of life through processes like natural selection and descent with modification. According to Darwin, species evolve over time due to variations in individuals, with those possessing advantageous traits being more likely to survive and reproduce.

Darwin and his theory of evolution3

Darwin and his theory of evolution

what's the ultimate source of variations

evolution was seen to depend on genetic mutation and naturl selection
the variations produced in these inherited traits is the raw material on which natural selection acts
mendal shows that organisims acquire traits through discrte units of heridity which later(genes)

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

natural selection of varients explaned observations on the geography of species differences
those who have heritable characteristics enable them to survive and pass those characteristics to their offspring
there are differences betwwen offspring that survive and reproduce and those who don't

Darwin's propositions

NATURAL SELECTION was the process by which new species were brought into existence
Species arose by COMMON DESCENT, as a result of DIVERGENCE from a COMMON STOCK
This PRINCIPLE OF DIVERGENCE is the most important factor in the evolution of new species
All species are characterised by variation between individuals
this will urge the tendency for varieties to be distinct successive generations
if a change occurs in the physical environment, individuals will be exposed to new circumstancesso individuals'll try to adapt
Artificial selection has a marked effect on the domesticated plants and animals, although it is applied for a small number of generations

the importance of his voyage to galpage islands

he noticed different finches which helped him to develop his propositions

Responses to his misunderstandings

in the scientific community there are thousands of scientists who are devoutly religious and also accept evolution
Evolution is both observable and testable
genetic mutation e.g. in fruit flies
A rtificial selection in the laboratory
Study of living species e.g. Darwin’s Finches
the fossil record
Fossilization is a very rare event. There must be specific conditions for a creature to be fossilized
The origin of life is not the main focus of evolutionary theory but rather the way life changes after its origin
Natural selection does weed out individuals unfit for a particular environment but conditions are changing

darwin's misunderstandings

Evolution and religion are incompatible
Because evolution is not observable or testable it is not science.
fossil record is not complete shows evolutionary theory to be false
Evolutionary theory is a theory about the origin of life.
Evolution is a “ladder of progress”, a steady march of progress with organisms constantly getting better

what's evolution

Darwin called this process "descent with modification," and it remains a good definition of biological evolution today
It explains that living things share common ancestors.
Galaxies, stars, the solar system, and earth have changed through time, and so has life on earth.
explains that what we see today is different from what existed in the past