EvolutionEvolution

To understand the theory of evolution, and to evaluate the evidence this is based on

Wednesday, April 19, 2023

EvolutionEvolution

Darwin’s theory of evolution explains how species of living things have changed over time

The theory is supported by evidence from fossils, and by the rapid changes that can be seen to occur in microorganisms such as antibiotic-resistant bacteria

Many species have become extinct in the past and the extinction of species continues to happen…

Charles DarwinCharles Darwin

Charles Darwin was an English naturalist who studied variation in plants and animals during a five-year voyage around the world in the 19th century onboard HMS Beagle

He explained his ideas about evolution in On the Origin of Species, published in 1859

Darwin’s ideas caused a lot of controversy, and this continues to this day, because the ideas can be seen as conflicting with religious views about the creation of the world and creatures in it

Darwin’s FinchesDarwin’s Finches

Darwin studied the wildlife on the Galápagos Islands - a group of islands on the equator almost 1,000km west of Ecuador

He noticed that the finches (songbirds) on the different islands were fundamentally similar to each other, but showed wide variations in their size, beaks and claws from island to island (their beaks were different depending on the local food source)

Darwin concluded that, because the islands are so distant from the mainland, the finches that had arrived there in the past had changed over time – proposing his theory of evolution via natural selection…

Darwin’s FinchesDarwin’s Finches

The finches on the different islands were fundamentally similar to each other, but showed wide variations in their size, beaks and claws from island to island (their beaks were different depending on the local food source)

EvolutionEvolution

The basic idea behind the theory of evolution is that all the different species have evolved over millions of years from simple life forms

These simple life forms first developed more than three billion years ago (Earth is about 4.5 billion years old)

FossilsFossils

Fossils provide evidence for evolution, showing how today’s species have changed and developed over millions of years

There are quite a few ‘missing links’ though, as the fossil record is incomplete as very few dead plants and animals actually turn into fossils (most simply decay away)

Darwin & LamarckDarwin & Lamarck

Darwin wasn’t the first to come up with evolution – he was simply the one credited with explaining how it worked (i.e. via natural selection)

An earlier scientist called Lamarck explained evolution by different means...

Lamarck looked at giraffes and concluded they have long necks because the giraffe stretches its neck to reach the food, and these long necks are passed on to their offspring

He stated organs which aren’t used will eventually disappear

Life On EarthLife On Earth

Complete the life on Earth worksheet

Life On EarthLife On Earth

Evolutionary StruggleEvolutionary Struggle

Up to the 18th Century the vast majority of people believed God created the world

At the beginning of the 19th century scientists came up with new ideas: - Lamarck and the inheritance of acquired

characteristics, all animals evolved from worms… Darwin and natural selection

Darwin’s ideas were at the time seen to go against the creationist views of the church (which had a great deal of influence and power) – it took many years before Darwin’s ideas to be accepted

Evolutionary StruggleEvolutionary Struggle

Darwin’s theory challenged the idea that God made all the animals and plants on Earth – acceptance did not come easily…

At the time Darwin struggled with finding evidence to convince scientists (it took many years for scientists to collect data and view the world differently)

The mechanisms of inheritance were also not understand at the time of publication, but once this was discovered the theory became accepted…

Modern StruggleModern Struggle

Currently there are strong arguments that creationism should be taught in schools – in some American schools it is illegal to teach evolution (but then what religion should you teach)?!

Christianity / Buddhism / The Church Of The Flying Spaghetti Monster?!

Science and religion often clash on specific areas, yet science is rooted on being able to prove / disprove ideas based on evidence – religion based on faith / spiritualism does not require proof

Earth AgeEarth Age

Science and religion have clashed on the age of the Earth – in the 17th Century creationism was largely unquestioned, with Archbishop Usher calculating the age of the Earth being less than 6000 years old!

Scientists disproved this with a variety of evidence: - New lands with animals and plants were discovered through

increased travel during the 18th Century – fossils showed huge changes throughout the Earth’s history

In the 19th Century the British geologist Sir Charles Lyell showed the Earth to be very ancient, being shaped by rivers and ‘subterranean fires’ – he estimated the Earth to be several hundred million years old

Darwin, along with fossil evidence, came up with the idea of evolution (yet some still believed the fossils were put into rocks so God could test their faith)

By the 1980’s Arthur Holmes used radioactivity to date rocks – establishing the age of the Earth to be around 4.6 billion years old – plenty of time for evolution to have happened!

Science Versus ReligionScience Versus Religion

Complete the science versus religion worksheet

As you complete the worksheet discuss your ideas amongst your table – is anyone highly opinionated with this debate?

Clockwork OriginClockwork Origin