How old is the earth? Evolutionist think the earth is about 4.5 billion years old.

Scientist can determine the ages of rocks using absolute dating and relative dating methods. Relative dating does not provide the actual age in years of a rock. Rather, it describes whether a particular rock layer is younger or older than the other layers. You just studied 3 terms!

Index fossils are useful because they tell the relative age of the rock layers in which they occur.

Radio metric dating is a method used to show the age of rocks by measuring the amounts of radioactive substance found in rocks.

The best estimate for Earth’s age is based on radiometric dating of fragments from the Canyon Diablo iron meteorite. From the fragments, scientists calculated the relative abundances of elements that formed as radioactive uranium decayed over billions of years.

4.543 billion years

a. Georges Louis Leclerc

All the analyses indicate that land plants first appeared about 500 million years ago, during the Cambrian period, when the development of multicellular animal species took off.

Four (4) conditions for natural selection. Four conditions are needed for natural selection to occur: reproduction, heredity, variation in fitness or organisms, variation in individual characters among members of the population. If they are met, natural selection automatically results.

Natural selection is a process whereby genes are selected randomly for preservation in the next generation. Natural selection occurs in opposition to evolution. Natural selection favors individuals that reproduce more than others. Natural selection can be used by farmers to generate organisms with desirable traits.

*Natural selection favors individuals that reproduce more than others. Individuals experience differential success in their ability to survive or reproduce. (Why: variation in fitness is required for selection to change the characteristics of a population over time.

The correct statement is – Natural Selection is the process by which ‘organisms with more beneficial traits’ are likely to survive and reproduce. EXPLANATION: Natural selection is the process of ‘differential survival’ and ‘reproduction in organisms’ that have different phenotype.

A: Natural selection cause advantageous variation to become more common over many generations. B: Only variation that help individuals avoid predators can become more common through natural selection. C: Natural selection can cause an individual to gain new advantageous variation during its life.

Allopatric speciation. -first step:consequence. – this is the most widely accepted form of speciation. — the first step in the process is the geographic separation of two populations of the same species. -consequence:it eliminates the movement of genes between the two populations.

In eukaryotic species—that is, those whose cells possess a clearly defined nucleus—two important processes occur during speciation: the splitting up of one gene pool into two or more separated gene pools (genetic separation) and the diversification of an array of observable physical characteristics (phenotypic …

The correct CORRECT answer is: “The population become adapted to different environments and eventually become so different that they cannot interbreed to produce fertile offspring.”

THE MAGICAl ROAD TO EVOLUTION

• First Stage: Separation. Speciation usually begins when a part of a population becomes separated from the rest of their species.
• Second Stage: Adaptation.
• Third Stage: Reproductive Isolation.
• Did you know?

New species form by speciation, in which an ancestral population splits into two or more genetically distinct descendant populations. Speciation involves reproductive isolation of groups within the original population and accumulation of genetic differences between the two groups.

Gene flow is also called gene migration. Gene flow is the transfer of genetic material from one population to another. Gene flow can take place between two populations of the same species through migration, and is mediated by reproduction and vertical gene transfer from parent to offspring.