Evolution

Fossils or natural selection

Lyell's theory of uniformitarianism, which proposed that geological processes occurring in the past are the same as those observed today, influenced Darwin's understanding of deep time and gradual change. This helped Darwin conceive of evolution as a slow, natural process that could explain the diversity of life. By accepting uniformitarianism, Darwin could propose that natural selection acted over vast periods of time to shape the development of species.

An acanthodian is a member of a group of extinct fish which existed from the Silurian to the Permian period.

Lamarck knew evolution was happening, his inaccuracies are in how he explained it.

The first part of his theory is known as "use it or lose it" today. He said that use makes organs and structures bigger or more useful. Giraffes needed long necks, while blind cave fish lost their eyes. Darwin thought this idea was too simple, and replaced it with natural and sexual selection.

The second major point Lamarck made was called acquired inherited traits. This means that traits that an organisms gets after it was born affects its offspring. This would mean that a bodybuilder would naturally get buff children, and that crabs that lost their claws would have clawless spawn. A famous experiment involving the mutilation of mice (which left their offspring unaffected) disproved this.

Because of our knowledge of genetics, we say that variation is caused by mutations and not acquired traits.

James Hutton is often regarded as the father of modern geology, and his contributions laid the groundwork for evolutionary theory. He proposed the concept of deep time, suggesting that the Earth is much older than previously thought, allowing for gradual changes in organisms over long periods. His idea of uniformitarianism—that the processes shaping the Earth today are the same as those in the past—implied that the same slow, continuous processes could lead to significant biological changes over time, influencing later thinkers like Charles Darwin.

Most, but not all, scientists agree with Stephen Hawking and others who say that the entire universe (or more than one) blasted out of a tiny "thing" in a process nicknamed the Big Bang. The Big Bang flung huge amounts of matter out and away from itself in gigantic clouds of something like dust.

The cloud of dust began swirling for various reasons in all directions, and eventually some of the swirling dust came together at the center of its own particular swirl. As the dust particles came closer and closer within the swirl, they started attracting each other by the force of gravity more than they had before.

Getting closer increased the force of gravity even more. Pretty soon . . . millions of years . . . the particles of dust attracted each other so hard that they 'fell' together with a common center.

Those tight swirls of dust that had a big enough mass created intense heat (due to the force of gravity) that a nuclear reaction started, and the swirl became a star, just like our Sun, and emitted a monstrous amount of radiation - some in the form of heat, some in the form of light, some in the form of cosmic rays and gamma rays, and so on.

Smaller swirls nearby eventually turned into planets . . . if these new 'proto' planets were in the right place, they would orbit the new star and become a star system. We call our star system by the name of its star, "Sol". (sawl) So our star system is called the Solar (Sol-ar) (SOLE-uhr) System.

Evolutionary trees show the relationships between organisms based on their shared ancestry and genetic similarities. They depict the pattern of evolutionary history and common descent between different species, suggesting how they are related and evolved over time. These trees can help scientists understand the evolutionary processes that have shaped the diversity of life on Earth.

A discovery that shows species appearing suddenly in the fossil record without any preceding ancestors would provide evidence against the theory of evolution. This would contradict the gradual changes in species predicted by evolution.

One key piece of biochemical evidence that supports biological evolution is the similarity in DNA sequences among different species. By comparing the DNA sequences of organisms, scientists can uncover evolutionary relationships and common ancestry. Additionally, the presence of vestigial structures and shared biochemical pathways among different species further support the idea of a common evolutionary origin.

Beginning in 1801, Lamarck began to publish details of his evolutionary theories. Where others in the field had hinted at the possibility of evolutionary change, Lamarck declared it as being a truth and fact.

Microevolution refers to small-scale changes in allele frequencies within a population over a short period of time. These changes can include factors such as genetic drift, mutations, natural selection, and gene flow within a population. Microevolution is responsible for the variation we see within species.

Darwin's findings, such as natural selection, provide evidence for microevolution, which involves changes within a species over time. However, they do not offer direct evidence for macroevolution, which involves the formation of new species or higher taxa over long periods. Macroevolution typically requires additional mechanisms, like genetic mutations and genetic drift, to account for larger-scale changes.

Evolution, as a biological process, began with the emergence of life on Earth, estimated to have occurred around 3.5 to 4 billion years ago. The mechanisms of evolution, such as natural selection and genetic mutation, have been shaping species continuously since then. The fossil record shows evidence of significant evolutionary changes over time, particularly during events like the Cambrian Explosion around 541 million years ago, when many major groups of animals appeared. Thus, evolution is an ongoing process that has been happening for billions of years.

The five fingers of evolution refer to five major principles that explain how evolution works: genetic variation, competition for resources, natural selection, adaptation, and speciation. These concepts help us understand how species change and evolve over time in response to their environment.

Alfred Russel Wallace, a contemporary of Charles Darwin, independently proposed a theory of evolution by natural selection that was similar to Darwin's. Wallace's work on natural selection prompted Darwin to publish his own views on the subject. The two scientists jointly presented their work in a paper in 1858.

which model of evolution shows change over a relatively short period fo time

Anthropologists and archaeologists study artifacts, genetic data, and cultural practices to trace patterns of human migration. They use a combination of archaeological evidence, linguistic studies, and genetic analysis to develop theories about how populations moved and interacted over time. By comparing findings from different regions and time periods, they can piece together a comprehensive understanding of human migration patterns.

Three key influences on the selection process are organizational policies and procedures, legal considerations such as anti-discrimination laws, and the specific job requirements and competencies needed for the role. These factors help shape the criteria used to evaluate candidates and ensure a fair and effective selection process.

The punctuated equilibrium theory suggests that evolution occurs in rapid bursts of change interspersed with long periods of stasis. It proposes that species experience sudden bursts of evolutionary change due to localized environmental pressures, followed by extended periods of little to no change. This theory contrasts with the gradualism model, which suggests a constant and gradual rate of evolution over time.

Jean-Baptiste Pierre Antoine de Monet, Chevalier de Lamarck, and also known as simply Lamarck was born on August 1, 1744 and died on December 18, 1829. He was a French naturalist. Lamarck was one of the first believers in evolution and practiced natural laws. He also coined the term "Biology."

Ewan ko

creation

Of course. Evolution has happened ever since life first came into existence on Earth, some 3.5 billion years ago.