Neanderthal Genetics Quiz
42 Questions
1 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Which population has the highest percentage of Neanderthal DNA according to the data?

  • South Asians
  • Australians
  • West Africans
  • East Asians (correct)

What chromosome was found to contain very little Neanderthal DNA?

  • X chromosome (correct)
  • Mitochondrial DNA
  • Autosomes
  • Y chromosome

What is the primary reason for the variation in Neanderthal DNA percentage among different populations?

  • Population isolation
  • Genetic mutation rates
  • Different migration patterns (correct)
  • Varying environmental pressures

Which of the following groups has been shown to completely lack Neanderthal DNA?

<p>East Africans (A)</p> Signup and view all the answers

What do the red lines in the analysis represent?

<p>Regions with Neanderthal sequence variants (B)</p> Signup and view all the answers

What percentage of Neanderthal DNA is identical to modern human DNA?

<p>99.7% (C)</p> Signup and view all the answers

What was the primary source of sequence data in the DNA extracts from Vindija cave?

<p>Non-primate organisms (A)</p> Signup and view all the answers

Which of the following was used to conduct additional sequencing of Neanderthal DNA?

<p>Three samples from Vindija cave (D)</p> Signup and view all the answers

Which component was NOT mentioned in relation to Neanderthal genetics?

<p>Human nuclear DNA (D)</p> Signup and view all the answers

If two Neanderthal samples have identical mtDNA, what does this suggest?

<p>They may belong to the same individual (B)</p> Signup and view all the answers

How was the Neanderthal genome initially sequenced?

<p>By BLAST analysis (D)</p> Signup and view all the answers

How many base pairs of Neanderthal DNA were sequenced in the mentioned study?

<p>65,250bp (D)</p> Signup and view all the answers

What type of tube is referenced in the context of working with bacteria?

<p>Eppendorf tube (D)</p> Signup and view all the answers

Why did early research into ancient DNA primarily focus on sequencing mitochondrial DNA (mtDNA)?

<p>mtDNA sequences are well-preserved and more abundant (C), mtDNA is easier to analyze than nuclear DNA (D)</p> Signup and view all the answers

What is one of the main challenges when attempting to sequence ancient DNA?

<p>The DNA sequence of Neanderthals is unknown beforehand (C)</p> Signup and view all the answers

How did researchers attempt to sequence Neanderthal DNA when sequences were unknown?

<p>By cloning fragments from the DNA sample directly (A)</p> Signup and view all the answers

What is the approximate length of a Neanderthal mitochondrial genome based on published research?

<p>16,565 base pairs (B)</p> Signup and view all the answers

What organism's DNA was extracted from a 38,000-year-old specimen in Croatia for sequencing?

<p>Neanderthals (C)</p> Signup and view all the answers

What does the ring structure in the diagram discussed in the context of DNA represent?

<p>The structure of mitochondrial DNA (A)</p> Signup and view all the answers

What is the length of human mitochondrial DNA for comparison?

<p>16,569 base pairs (C)</p> Signup and view all the answers

What was a significant year when a complete Neanderthal mitochondrial genome sequence was published?

<p>2008 (C)</p> Signup and view all the answers

What percentage of modern human DNA is identical to Neanderthal DNA?

<p>99.7% (A)</p> Signup and view all the answers

Which population has been found to have Neanderthal introgression in their genomes?

<p>All non-Africans (D)</p> Signup and view all the answers

What is the average size of haploblocks indicating variation in Neanderthals and non-Africans?

<p>50,000 bp (C)</p> Signup and view all the answers

How much of some modern human genomes have been found to be of Neanderthal origin?

<p>4% (D)</p> Signup and view all the answers

Based on nuclear DNA comparisons, Denisovans are more closely related to which group?

<p>Neanderthals (A)</p> Signup and view all the answers

Where was the first Neanderthal fossil discovered?

<p>Neander Valley (A)</p> Signup and view all the answers

How long ago did Neanderthals likely disappear?

<p>30,000-40,000 years ago (A)</p> Signup and view all the answers

What characteristic is NOT associated with Neanderthal skeletal structure?

<p>Long, slender limbs (D)</p> Signup and view all the answers

What is a consequence of genetic bottlenecks?

<p>Low level of genetic diversity (D)</p> Signup and view all the answers

What is thought to have contributed to Neanderthal extinction?

<p>Competition with humans and climate change (A)</p> Signup and view all the answers

What does bottlenecking refer to in population genetics?

<p>Drastic reduction in population size (A)</p> Signup and view all the answers

Which statement is true about Neanderthals and modern humans?

<p>Neanderthals and modern humans co-existed for 30,000-40,000 years (D)</p> Signup and view all the answers

Which factor is debated as a contributor to Neanderthal extinction?

<p>Genetic diversity levels (D)</p> Signup and view all the answers

What percentage of Denisovan DNA is found in Australians?

<p>4% (A)</p> Signup and view all the answers

Which species is estimated to have lived between ~400,000 to ~30,000 years ago?

<p>Neanderthals (D)</p> Signup and view all the answers

Which feature is notably associated with Homo floresiensis?

<p>Small stature of about 3.5 ft tall (B)</p> Signup and view all the answers

What is believed to have occurred between Denisovans and modern humans?

<p>Interbreeding (A)</p> Signup and view all the answers

Why is less known about the genome of Homo floresiensis?

<p>Their DNA degrades faster in warmer climates (C)</p> Signup and view all the answers

What is the maximum estimated length of time from which DNA can be recovered?

<p>1 million years (A)</p> Signup and view all the answers

What percentage of Denisovan DNA is found in East Africans?

<p>0.1% (C)</p> Signup and view all the answers

Which of these hominin species is not believed to have co-inhabited with Homo sapiens?

<p>Homo habilis (A)</p> Signup and view all the answers

Flashcards

Mitochondrial DNA (mtDNA)

DNA found in the mitochondria, small organelles responsible for energy production in cells.

Why was mtDNA the focus of early ancient DNA research?

Mitochondrial DNA is present in many copies per cell, making it easier to extract and sequence from degraded ancient samples.

Challenges of Ancient DNA Sequencing

Ancient DNA is fragmented and degraded, making it difficult to sequence. The unknown DNA sequence of extinct species adds to the challenge.

PCR for Ancient DNA

A technique using primers designed for human DNA to amplify sections of ancient DNA, hoping they match.

Signup and view all the flashcards

Cloning Ancient DNA

Directly cloning fragments of ancient DNA from the sample to sequence them.

Signup and view all the flashcards

Neanderthal Mitochondrial Genome

The complete DNA sequence of mitochondria from a Neanderthal individual, containing 16,565 base pairs.

Signup and view all the flashcards

Nuclear Genome vs. mtDNA

While mtDNA provides information about the maternal lineage, the complete nuclear genome offers a broader picture of an ancient species.

Signup and view all the flashcards

Ring Structure in Ancient DNA Diagram

Represents a circular mitochondrial DNA molecule.

Signup and view all the flashcards

Neanderthal Chromosome

A chromosome found in Neanderthals, a species of ancient humans. It carries genetic information, similar to human chromosomes, but with some differences.

Signup and view all the flashcards

Bacterial Chromosome

A single, circular DNA molecule found in bacteria. It contains all the essential genes for bacterial survival and reproduction.

Signup and view all the flashcards

Plasmid

A small, circular DNA molecule found in bacteria, separate from their main chromosome. It carries additional genes that can provide benefits like antibiotic resistance.

Signup and view all the flashcards

Eppendorf tube

A small, conical tube used in laboratories to hold and centrifuge small volumes of liquids, often used in genetic research.

Signup and view all the flashcards

Sequencing Neanderthal Genome

The process of determining the complete sequence of DNA bases in the Neanderthal genome, revealing their genetic makeup and evolutionary history.

Signup and view all the flashcards

Vindija Cave

A cave in Croatia where Neanderthal remains were discovered. This location provided important samples for sequencing the Neanderthal genome.

Signup and view all the flashcards

mtDNA

Mitochondrial DNA, the DNA found in the mitochondria, responsible for energy production. It is inherited maternally.

Signup and view all the flashcards

Neanderthal DNA in Humans

The genomes of non-African humans contain Neanderthal DNA sequences, indicating interbreeding between Neanderthals and early modern humans.

Signup and view all the flashcards

Autosomes and Neanderthal DNA

Neanderthal DNA is found on most autosomes, which are the chromosomes that are not sex chromosomes.

Signup and view all the flashcards

Geographic Variation in Neanderthal DNA

Different populations around the world have varying amounts of Neanderthal DNA, with Europeans and East Asians having significantly more than West Africans.

Signup and view all the flashcards

Introgression

Introgression refers to the transfer of genetic material from one species to another through interbreeding. In this case, Neanderthal DNA was introduced into the modern human gene pool.

Signup and view all the flashcards

Neanderthal and Human DNA Similarity

The DNA of Neanderthals and modern humans is remarkably similar, sharing 99.7% of their genetic material.

Signup and view all the flashcards

Haploblocks: Evidence of Introgression

Haploblocks are DNA regions where Neanderthal and non-African human sequences align better than African human sequences, suggesting interbreeding.

Signup and view all the flashcards

Introgression of Neanderthal DNA

The process where Neanderthal DNA integrated into the genome of modern humans after interbreeding, particularly in non-African populations.

Signup and view all the flashcards

Denisovans: A New Hominin Species

Denisovans are an extinct human species identified from a finger bone and teeth found in Denisova Cave, Siberia, distinct from Neanderthals.

Signup and view all the flashcards

Denisovan-Neanderthal Relationship

Denisovans are more closely related to Neanderthals than either is to modern humans, based on nuclear DNA comparisons.

Signup and view all the flashcards

Neanderthal

An extinct species of human that lived in Europe and Asia from about 400,000 to 40,000 years ago.

Signup and view all the flashcards

Neanderthal Skull

Neanderthals had a low, flat, elongated skull, different from modern humans.

Signup and view all the flashcards

Neanderthal Adaptations

Neanderthals had adaptations for a cold climate, including a barrel-shaped rib cage and short, bowed shoulder blades.

Signup and view all the flashcards

Neanderthal Tools

Neanderthals used sophisticated tools, evidence of their intelligence and ability to adapt.

Signup and view all the flashcards

Genetic Bottleneck

A drastic reduction in population size, often due to a catastrophic event.

Signup and view all the flashcards

Bottleneck Effect

The reduction in genetic diversity due to a genetic bottleneck.

Signup and view all the flashcards

Neanderthal Extinction

While the exact cause of Neanderthal extinction is debated, possible contributors include competition with humans, climate change, and reduced genetic diversity.

Signup and view all the flashcards

Interbreeding with Neanderthals

Some evidence suggests that Homo sapiens interbred with Neanderthals after leaving Africa.

Signup and view all the flashcards

Denisovans

An extinct hominin species closely related to Neanderthals, known from fossils discovered in Denisova Cave in Siberia.

Signup and view all the flashcards

Interbreeding with Modern Humans

Denisovans and modern humans interbred, with evidence showing small amounts of Denisovan DNA in modern populations, particularly in Melanesians and Australians.

Signup and view all the flashcards

Genetic Diversity of Denisovans

Genetic analysis of Denisovan remains shows high genetic diversity, similar to that found in Neanderthals across Eurasia.

Signup and view all the flashcards

Homo floresiensis

An extinct human species known as 'hobbits' due to their small stature, discovered on the island of Flores, Indonesia.

Signup and view all the flashcards

Adaptation to Island Environment

The small size of Homo floresiensis may be a result of adapting to the limited resources available on the island of Flores, similar to the evolution of small stegodonts on the same island.

Signup and view all the flashcards

DNA Degradation in Warm Climates

Warm climates accelerate the degradation of DNA, making it challenging to study the genome of Homo floresiensis as compared to Neanderthals who lived in colder regions.

Signup and view all the flashcards

Shared Ancestry

Neanderthals, Denisovans, and Homo sapiens all share a common ancestor, with evidence suggesting they co-existed on Earth at different time periods.

Signup and view all the flashcards

Hominin Species Timeline

Neanderthals existed between 400,000 and 30,000 years ago, Denisovans between 400,000 and 30,000 years ago, and Homo floresiensis between 100,000 and 50,000 years ago.

Signup and view all the flashcards

Study Notes

Ancient DNA

  • Several archaic hominin species coexisted with Homo sapiens.
  • Modern genomic methods allow the study of extinct species' genomes.
  • Homo sapiens that left Africa interbred with Neanderthals and Denisovans.

Objectives

  • Students will apply concepts like sequencing, population genetics, and organellar DNA to understand archaic genome research.

Schedule

  • Monday: Review Session (12:30 PM - 2:00 PM), Lennon 206
  • Tuesday: Review Session (2:00 PM - 3:30 PM), Lennon 206
  • Wednesday: Final Exam (8:00 AM - 10:00 AM)

Svante Pääbo

  • A Swedish geneticist, Svante Pääbo, won the 2022 Nobel Prize in Physiology or Medicine for his work on extinct hominin genomes.
  • He was the first to successfully extract and sequence ancient DNA from a Neanderthal.
  • Pääbo and his team completed a draft reference sequence of the Neanderthal genome in 2009.

Ancient DNA Study Intersections

  • Reference sequences
  • Cloning
  • Population genetics
  • mtDNA

Hominin Species

  • Neanderthals: ~400,000 to ~30,000 years ago
  • Denisovans: ~400,000 to ~30,000 years ago
  • Homo floresiensis: ~100,000 to ~50,000 years ago

Challenges of Ancient DNA

  • Very little DNA can be recovered from samples.
  • Samples are not easy to come by.
  • Ancient DNA is often contaminated from soil microbes and human handling.
  • Ancient DNA fragments are degraded. Generally only 100-200 base pairs long.
  • Recovery is done in a cleanroom

Early Focus on mtDNA

  • Much of the earliest ancient DNA research focused on mitochondrial DNA (mtDNA) sequencing.
  • mtDNA's circular structure and higher copy number made it easier to extract from degraded samples.

Sequencing Neanderthal DNA

  • A complete Neanderthal mitochondrial genome sequence was published in 2008 (16,565 base pairs).
  • DNA was extracted from a 38,000-year-old Neanderthal specimen.
  • Neanderthal genomic sequencing involved extracting, cloning, small-scale sequencing, and batch culture steps

Sequencing the Neanderthal Genome

  • 95-99% of sequence from DNA extract of Neanderthal samples were determined to be from non-primate origin (mostly microbes).
  • A draft of the complete Neanderthal genome was published in 2010; mtDNA from three different samples was compared.
  • Neanderthal DNA was found to be 99.7% identical to modern human DNA.

Neanderthals

  • First fossil discovered in Neander Valley, Germany (1856)

  • Fossils date back ~400,000 years ago; disappeared ~30,000-40,000 years ago.

  • Physical features – low, flat, elongated skull, barrel-shaped rib cages, short, bowed shoulder blades.

  • Adapted to cold environment; used tools; suffered frequent injuries.

  • Range included Europe and southwest and central Asia.

  • Co-existed with Modern humans approximately 30,000-40,000 years ago, unclear how much interaction there was.

Bottlenecking

  • Neanderthal populations experienced an extended period of bottlenecking (population drastically reduced in size).
  • This results in a very low level of genetic diversity and a different frequency of alleles in surviving populations from the original population.

Interbreeding

  • If interbreeding occurred, traces of Neanderthal DNA should be present in the descendants.
  • Introgression: a transfer of DNA from one species to another through mating.
  • Admixture: DNA indicates that different populations interbred.

Determining Neanderthal/Homo Sapien Interbreeding

  • Neanderthal sequences were aligned to Homo sapiens genome sequences.
  • Neanderthal DNA found in the autosomes of non-African populations; very little found on the X chromosome.
  • Worldwide distribution of Neanderthal DNA shows varying percentages (e.g., Europeans 2%, East Asians 3%).

Denisovans

  • Discovered in Denisova Cave, Altai Mountains, Southern Siberia.
  • Identified in 2010 as representing a new hominin species through mtDNA sequencing.
  • Based on nuclear DNA comparisons Denisovans are more closely related to Neanderthals than to modern humans.
  • Denisovans shared a common ancestor with Neanderthals about 400,000 years ago.
  • DNA from a single Denisovans location shows comparable genetic diversity as that of Neanderthals from Eurasia.
  • Interbreeding with modern humans occurred, evidence in DNA of Eurasians and Australians (e.g., Melanesians 5%).

Homo floresienesis

  • Estimated to be ~3.5 ft tall.
  • Fossils discovered on the island of Flores, Indonesia (2003)
  • Small size may be adaptation to limited resources on an island.
  • Used stone tools, but little DNA is known.

DNA Degradation

  • DNA degrades over time. The maximum length of time DNA can be recovered is about 1 million years.
  • Extinct dinosaurs (65 million years ago) have no recoverable DNA.

Reminders for this week

  • One more office hour today.
  • No more late assignments will be accepted.
  • Review sessions on Monday and Tuesday in Lennon 206.
  • Final exam on Wednesday, December 11th at 8:00am.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

Ancient DNA PDF

Description

Test your knowledge on Neanderthal DNA, its variation among populations, and the significance of genetic findings. This quiz covers questions related to Neanderthal percentages, chromosome analysis, and sequencing methods, providing insights into ancient human relatives and their genetic legacy.

More Like This

Use Quizgecko on...
Browser
Open
Browser
Browser