Question

Biological evolution is the summation of changes that have occurred as a result of ____________ . The first living organisms were likely ____________ that evolved 3.5 billion years ago. Approximately 2.1 billion years ago the first ____________ were thought to have evolved. However, it was not until 700 million years ago that the first ____________ organisms evolved, meaning that they have existed for less than 20% of Earth's life history. Because all living organisms evolved from a single common ancestor, they are fundamentally ____________ in their characteristics.

Answer 1

Ans. Biological evolution is the summation of changes that have occurred as a result of genetic mutations and natural selection. The first living organisms were likely RNA-based cells (Protocell) that evolved 3.5 billion years ago. Approximately 2.1 billion years ago the first eukaryotic cell were thought to have evolved. However, it was not until 700 million years ago that the first multicellular animals organisms evolved, meaning that they have existed for less than 20% of Earth's life history. Because all living organisms evolved from a single common ancestor, they are fundamentally similarity in their characteristics.

# Evolution is the process of occurrence of genetic mutations and the preservation of these mutations in the population through natural selection. If a genetic mutation is not retained in the population through natural selection, that trait can’t persist in the population. Neither would that trait evolve because it couldn’t be retained in population to exhibit evolution.

# The first cell to evolve was RNA-based cell (a cell having RNA as its genetic material, also called Protocell). Protocells evolved around 3.5 billion years ago.

# First multicellular organism (plant) evolved around 1.2 bya. It was an algae.

# First multicellular animal evolved around 700 bya.