Evolution (Level 5) Flashcards
How did the Earth form over 4.6 billion years ago?
Out of a mixture of dust and gas around the young sun.
What were the earliest life forms we know of that left signals of their presence in rocks about 3.7 billion years old?
Microscopic organisms (microbes)
How long ago did the first known single-celled organisms appear on Earth?
About 3.5 billion years ago- roughly a billion years after Earth formed.
What forms of life took longer to evolve than the first known single-celled organisms?
More complex forms of life.
When did the first multicellular organisms appear on Earth?
Not until about 600 million years ago.
How long ago did eukaryotes develop?
At least 2.7 billion years ago, following some 1 to 1.5 billion years of prokaryotic evolution.
How long ago did archaic Homo sapiens evolve?
About 300,000 years ago.
How long ago did modern Homo sapiens evolve?
Approximately 160,000 years ago.
During which period did the first fossil arthropods appear?
During the Cambrian period (541 to 485.4 million years ago).
What are represented by trilobites, merostomes, and crustaceans?
The first fossil arthropods.
What were present as well as trilobites, merostomes, and crustaceans during the Cambrian period?
Some enigmatic arthropods that do not seem to fit into any of the existing subphyla.
When did the first fish appear, before undergoing a long period of evolution so that, today, they are by far the most diverse group of vertebrates?
Around 530 million years ago.
When have researchers found land plants to have evolved on Earth?
About 700 million years ago.
When have researchers found land fungi to have evolved on Earth?
Around 1,300 million years ago.
Which research estimates have been found to be much earlier than previous estimates of around 480 million years ago, which were based on the earliest fossils of said organisms?
The research estimates of land plants having evolved on Earth about 700 million years ago, and land fungi having evolved around 1,300 million years ago.
