* . *
  • About
  • Advertise
  • Privacy & Policy
  • Contact
Thursday, August 7, 2025
Earth-News
  • Home
  • Business
  • Entertainment
    Themed Entertainment Design – Purdue Polytechnic

    Innovative Themed Entertainment Design: Creating Immersive Experiences

    Rachael Leigh Cook and Brandon Routh ‘Happy to Have Found Each Other’ Following Respective Divorces – yahoo.com

    Rachael Leigh Cook and Brandon Routh ‘Happy to Have Found Each Other’ Following Respective Divorces – yahoo.com

    ‘Billie Jean’ – Hyde Park Herald

    The Enduring Magic Behind ‘Billie Jean’ Revealed

    Hank Hill returns to a changed world in new ‘King of the Hill’ episodes – New Haven Register

    Hank Hill Navigates a Bold New World in Thrilling New ‘King of the Hill’ Episodes

    Exclusive | Fox Takes Stake in IndyCar Owner Penske Entertainment – The Wall Street Journal

    Exclusive | Fox Takes Stake in IndyCar Owner Penske Entertainment – The Wall Street Journal

    Go-to entertainment: why gaming was made for the toilet – The Guardian

    Why Gaming Is the Ultimate Way to Pass Time in the Bathroom

  • General
  • Health
  • News

    Cracking the Code: Why China’s Economic Challenges Aren’t Shaking Markets, Unlike America’s” – Bloomberg

    Trump’s Narrow Window to Spread the Truth About Harris

    Trump’s Narrow Window to Spread the Truth About Harris

    Israel-Gaza war live updates: Hamas leader Ismail Haniyeh assassinated in Iran, group says

    Israel-Gaza war live updates: Hamas leader Ismail Haniyeh assassinated in Iran, group says

    PAP Boss to Niger Delta Youths, Stay Away from the Protest

    PAP Boss to Niger Delta Youths, Stay Away from the Protest

    Court Restricts Protests In Lagos To Freedom, Peace Park

    Court Restricts Protests In Lagos To Freedom, Peace Park

    Fans React to Jazz Jennings’ Inspiring Weight Loss Journey

    Fans React to Jazz Jennings’ Inspiring Weight Loss Journey

    Trending Tags

    • Trump Inauguration
    • United Stated
    • White House
    • Market Stories
    • Election Results
  • Science
  • Sports
  • Technology
    BlackSky Technology Inc. (BKSY) Reports Q2 Loss, Lags Revenue Estimates – Yahoo Finance

    BlackSky Technology Inc. Reports Q2 Loss, Misses Revenue Targets

    Improved Technology Access: A Key to Closing the Healthcare Gap for African Americans – BIOENGINEER.ORG

    LMI Expands Technology Org, Appoints New Leaders – GovCon Wire

    LMI Expands Technology Team with Dynamic New Leadership Appointments

    Midland Innovation and Technology Charter School closing down – CBS News

    Midland Innovation and Technology Charter School Closes Permanently

    Future Trends In HR Technology – Dataconomy

    Future Trends In HR Technology – Dataconomy

    Nasdaq-listed Verb Technology to build $558 million TON treasury, rebrand as TON Strategy Co. – The Block

    Nasdaq-Listed Verb Technology to Build $558 Million TON Treasury and Rebrand as TON Strategy Co

    Trending Tags

    • Nintendo Switch
    • CES 2017
    • Playstation 4 Pro
    • Mark Zuckerberg
No Result
View All Result
  • Home
  • Business
  • Entertainment
    Themed Entertainment Design – Purdue Polytechnic

    Innovative Themed Entertainment Design: Creating Immersive Experiences

    Rachael Leigh Cook and Brandon Routh ‘Happy to Have Found Each Other’ Following Respective Divorces – yahoo.com

    Rachael Leigh Cook and Brandon Routh ‘Happy to Have Found Each Other’ Following Respective Divorces – yahoo.com

    ‘Billie Jean’ – Hyde Park Herald

    The Enduring Magic Behind ‘Billie Jean’ Revealed

    Hank Hill returns to a changed world in new ‘King of the Hill’ episodes – New Haven Register

    Hank Hill Navigates a Bold New World in Thrilling New ‘King of the Hill’ Episodes

    Exclusive | Fox Takes Stake in IndyCar Owner Penske Entertainment – The Wall Street Journal

    Exclusive | Fox Takes Stake in IndyCar Owner Penske Entertainment – The Wall Street Journal

    Go-to entertainment: why gaming was made for the toilet – The Guardian

    Why Gaming Is the Ultimate Way to Pass Time in the Bathroom

  • General
  • Health
  • News

    Cracking the Code: Why China’s Economic Challenges Aren’t Shaking Markets, Unlike America’s” – Bloomberg

    Trump’s Narrow Window to Spread the Truth About Harris

    Trump’s Narrow Window to Spread the Truth About Harris

    Israel-Gaza war live updates: Hamas leader Ismail Haniyeh assassinated in Iran, group says

    Israel-Gaza war live updates: Hamas leader Ismail Haniyeh assassinated in Iran, group says

    PAP Boss to Niger Delta Youths, Stay Away from the Protest

    PAP Boss to Niger Delta Youths, Stay Away from the Protest

    Court Restricts Protests In Lagos To Freedom, Peace Park

    Court Restricts Protests In Lagos To Freedom, Peace Park

    Fans React to Jazz Jennings’ Inspiring Weight Loss Journey

    Fans React to Jazz Jennings’ Inspiring Weight Loss Journey

    Trending Tags

    • Trump Inauguration
    • United Stated
    • White House
    • Market Stories
    • Election Results
  • Science
  • Sports
  • Technology
    BlackSky Technology Inc. (BKSY) Reports Q2 Loss, Lags Revenue Estimates – Yahoo Finance

    BlackSky Technology Inc. Reports Q2 Loss, Misses Revenue Targets

    Improved Technology Access: A Key to Closing the Healthcare Gap for African Americans – BIOENGINEER.ORG

    LMI Expands Technology Org, Appoints New Leaders – GovCon Wire

    LMI Expands Technology Team with Dynamic New Leadership Appointments

    Midland Innovation and Technology Charter School closing down – CBS News

    Midland Innovation and Technology Charter School Closes Permanently

    Future Trends In HR Technology – Dataconomy

    Future Trends In HR Technology – Dataconomy

    Nasdaq-listed Verb Technology to build $558 million TON treasury, rebrand as TON Strategy Co. – The Block

    Nasdaq-Listed Verb Technology to Build $558 Million TON Treasury and Rebrand as TON Strategy Co

    Trending Tags

    • Nintendo Switch
    • CES 2017
    • Playstation 4 Pro
    • Mark Zuckerberg
No Result
View All Result
Earth-News
No Result
View All Result
Home Science

Why do spiders have 8 legs?

July 23, 2023
in Science
Why do spiders have 8 legs?
Share on FacebookShare on Twitter

A close-up photo of a funnel-web spider on its web looking at the camera.

Here, we see all eight legs of a funnel-web spider. Spiders’ ancestors turned some appendages into fangs.
(Image credit: Amith Nag Photography via Getty Images)

There seems to be no ideal number of legs. Humans have two, dogs have four, insects have six and millipedes can have over 1,000. So what made spiders settle for eight legs? 

“I think the best answer and the simplest answer is that spiders have eight legs because their parents did,” Thomas Hegna, an assistant professor of invertebrate paleontology at the State University of New York at Fredonia, told Live Science. “But then that gets into sort of a regress, and somewhere this all had to start.”

If we follow the succession of eight-legged spider parents back to about 500 million years ago, during the middle Cambrian Period, we arrive at the root of the chelicerate lineage, the group of arthropods that contains spiders. If we go even further back, to 541 million years ago, we find the ocean-dwelling lobopods, the ancestors of all arthropods. 

The name “lobopod” doesn’t refer to a single species but rather a large variety of species with rather simple bodies. Basically, they were wormlike creatures with segmented bodies. Each segment featured roughly identical pairs of short, stubby legs, and this pattern continued along the lengths of their bodies. 

Related: What is the deadliest spider in the world?

We see an illustration of a wormlike marine creature with spikes on its back and many legs walking on the seafloor.

The spiky lobopod Hallucigenia lived during the Cambrian period. Notice that each segment has two appendages. (Image credit: dottedhippo via Getty Images)

As the lobopods evolved, they began specializing their legs and fusing body segments. The early chelicerates seem to have fused their small body segments into two big ones: the head and the abdomen. Scientists aren’t sure why, but the head kept the legs, and the abdomen lost them. By the time spiders appeared 315 million years ago, they inherited a body plan that was likely already 150 million years old.

It’s unclear which environmental pressures, if any, caused chelicerates to settle on their eight-legged arrangement. However, we know a great deal about where their legs came from — and it’s weird.

“Those legs are actually part of their mouth,” Nipam Patel, a developmental biologist and director of the Marine Biological Laboratory, which is affiliated with the University of Chicago, told Live Science. 

Because spiders, insects, crustaceans and millipedes all evolved from an ancestor that likely had a segmented body with a set of appendages on each segment, these species are just highly modified riffs on that basic plan. According to Patel, all arthropod appendages — including legs, antennae and even mandibles (the jaws) — can be traced back to a stubby lobopod appendage. 

Take a mantis shrimp. It swims with a bunch of little legs on a segmented abdomen. On the cephalothorax (a fused head and thorax) are its walking legs, and then near its mouth are little appendages that not only make up its jaws but also sweep food into its mouth to help it eat. 

We see a multicolored mantis shrimp (brown, green, blue, purple, yellow) walking on the colorful seafloor in Indonesia.

A peacock mantis shrimp (Odontodactylus scyllarus) walks along the seafloor in West Papua, Indonesia. Notice that it has a segmented abdomen with many appendages that help it swim. (Image credit: Reinhard Dirscherl/ullstein bild via Getty Images)

Compare that to an insect, whose abdomen doesn’t have appendages. But it has six legs on its thorax, while its head and mouth are basically set up like the mantis shrimp’s.

Then, there are spiders.

“If you look at a spider embryo, it looks exactly like an insect embryo,” Patel said. “Except it only grows the legs on its head. But instead of using those as mouthparts, it uses them to walk.”

The reason spiders walk with appendages from their faces goes back to lobopods and the original chelicerate body plan. While modern arthropods are spoiled for specialized appendages, the lobopods were wormlike creatures with many sets of roughly similar appendages. 

Related: What is the largest arachnid to ever live? 

“Initially, all of the legs were the same,” Heather Bruce, a research associate at the Marine Biological Laboratory, told Live Science. “But then the first appendages became differentiated for being a sensory appendage, like for sensing and grabbing food.”

From that point, the spider’s chelicerate ancestors began to diverge from the other groups. In the ancestors of insects and crustaceans, the lobopod’s multitasking front appendages lost their grabbing and feeding ability and became specialized sensory structures called antennae. But for chelicerates, those same appendages lost their sensory capabilities and became fangs. 

Meanwhile, chelicerates’ second leg pair evolved into a set of grabby appendages called pedipalps; the following four sets of legs remained in their role as walking legs, and all appendages after that were lost. 

Well, not all of them. “Spinnerets evolved from spider legs,” Bruce said. “There are really cool fossils in amber of a species that looks to be an ancestor of both spiders and scorpions, so it has some intermediate traits between the two. And on that fossil, there are very clear legs hanging off of the abdomen.”

Stay up to date on the latest science news by signing up for our Essentials newsletter.

Cameron Duke is a contributing writer for Live Science who mainly covers life sciences. He also writes for New Scientist as well as MinuteEarth and Discovery’s Curiosity Daily Podcast. He holds a master’s degree in animal behavior from Western Carolina University and is an adjunct instructor at the University of Northern Colorado, teaching biology. 

>>> Read full article>>>
Copyright for syndicated content belongs to the linked Source : Live Science – https://www.livescience.com/animals/spiders/why-do-spiders-have-8-legs

Tags: scienceSpiders
Previous Post

People on HIV meds have ‘almost zero’ chance of spreading virus via sex once levels are low

Next Post

Master copy of the Voyager Golden Record, designed as an audio postcard for intelligent aliens, is up for auction

A quilt-themed exhibit is coming to NYC’s American Folk Art Museum this fall – Time Out Worldwide

Discover the Magic of Quilts: Don’t Miss This Captivating NYC Exhibit This Fall!

August 7, 2025
Maximizing pasture potential, the science behind multi-species grazing – Beef Magazine

Unlocking the Power of Multi-Species Grazing: Science-Backed Strategies to Maximize Pasture Potential

August 7, 2025
The Council for Responsible Nutrition announces Science in Session theme and lineup – Nutritional Outlook

Council for Responsible Nutrition Reveals Thrilling Science in Session Theme and Speaker Lineup

August 7, 2025
Alibaba Upgrades Taobao Lifestyle Experience with New Cross-platform Loyalty Program – Alizila

Alibaba Upgrades Taobao Lifestyle Experience with New Cross-platform Loyalty Program – Alizila

August 7, 2025
BlackSky Technology Inc. (BKSY) Reports Q2 Loss, Lags Revenue Estimates – Yahoo Finance

BlackSky Technology Inc. Reports Q2 Loss, Misses Revenue Targets

August 7, 2025
Sports card industry leaders on what’s working and why trust needs to be improved – The New York Times

Sports card industry leaders on what’s working and why trust needs to be improved – The New York Times

August 7, 2025
‘Icy cool’: How Claudia Sheinbaum is navigating Trump’s new world order – Politico

Icy Cool’: How Claudia Sheinbaum Is Navigating the Challenges of a New Global Era

August 7, 2025
The U.S. Economy Is Stumbling Badly – Washington Monthly

The U.S. Economy Confronts Major Challenges Ahead

August 7, 2025

SM Entertainment revenue up, concert earnings flat – IQ Magazine

August 7, 2025
Has the Trump administration made America healthier? – EWG

Did the Trump Administration Improve America’s Health?

August 7, 2025

Categories

Archives

August 2025
MTWTFSS
 123
45678910
11121314151617
18192021222324
25262728293031
« Jul    
Earth-News.info

The Earth News is an independent English-language daily published Website from all around the World News

Browse by Category

  • Business (20,132)
  • Ecology (759)
  • Economy (782)
  • Entertainment (21,659)
  • General (16,337)
  • Health (9,821)
  • Lifestyle (792)
  • News (22,149)
  • People (783)
  • Politics (791)
  • Science (15,995)
  • Sports (21,279)
  • Technology (15,762)
  • World (764)

Recent News

A quilt-themed exhibit is coming to NYC’s American Folk Art Museum this fall – Time Out Worldwide

Discover the Magic of Quilts: Don’t Miss This Captivating NYC Exhibit This Fall!

August 7, 2025
Maximizing pasture potential, the science behind multi-species grazing – Beef Magazine

Unlocking the Power of Multi-Species Grazing: Science-Backed Strategies to Maximize Pasture Potential

August 7, 2025
  • About
  • Advertise
  • Privacy & Policy
  • Contact

© 2023 earth-news.info

No Result
View All Result

© 2023 earth-news.info

No Result
View All Result

© 2023 earth-news.info

Go to mobile version