Q:

What is the land bridge theory?

A:

Quick Answer

In the 19th and early 20th centuries, geologists hypothesized that major landmasses were once connected via an elaborate series of land bridges. This was an attempt to explain the distribution of plants and animals around the world, as it was recognized that populations could not have radiated across the world as they had with the continents in their present configuration.

Know More
What is the land bridge theory?
Credit: John Lund Blend Images Getty Images

Full Answer

The land bridge theory explained how life could have populated different continents by imagining an ever-increasing number of now-submerged land bridges. Though land bridges have existed in some places, such as the Bering land bridge that allowed humans to populate the Americas, the high number and irrational behavior of the proposed land bridges rendered the theory unworkable. By the early 20th century, one land bridge was supposed to have connected Brazil with Africa, which explained the similarities among African and South American rodents, and another bridge was supposed to have connected Europe with North America. Another bridge, or perhaps a lost continent called "Lemuria," was believed to have spanned the Indian Ocean. None of these land bridges and lost continents left any geological trace of their presence, and the theory was eventually scrapped with the acceptance of plate tectonics as a mechanism for continental drift.

Learn more about Anthropology

Related Questions

  • Q:

    How can you identify Indian burial grounds?

    A:

    Native American burial grounds are typically identified by bone fragments and ancient artifacts found in the earth in an area where Native Americans may have lived. Burial grounds are sometimes destroyed in the process of modern construction, leading to protests and outrage that goes ignored by some companies.

    Full Answer >
    Filed Under:
  • Q:

    Why are trilobites considered index fossils?

    A:

    Trilobites are considered index fossils because they are used to date geological strata via their presence. They specifically are used to date Paleozoic rock. Index fossils must be widespread, abundant, distinct and limited to a particular time period to be useful; trilobite fossils satisfy these requirements.

    Full Answer >
    Filed Under:
  • Q:

    What does a paleontologist do?

    A:

    Palaeontologists locate, collect and study fossils, according to the Falls of the Ohio State Park. Palaeontologists also record the history of life on Earth, ranging from the smallest bacteria to massive dinosaurs.

    Full Answer >
    Filed Under:
  • Q:

    What are the main differences between Homo erectus and Australopithecus?

    A:

    One of the key physiological differences between early humans (Homos) and Australopithecines was adult cranial capacity. On average, early humans had brains that were about 35 percent larger than Australopithecus africanus, who is widely considered to be one of two possible immediate ancestors of early humans — the other is Australopithecus garhi.

    Full Answer >
    Filed Under:

Explore