Question

Question

Prove whether temperature affects running speed in the Asian House Gecko via statistical analyses of data (tab-delimited format).

"temperature"            "speed"           "size"

"H"      90.1583707286065     101.496167405193

"H"      69.5326752074296     90.6680294417796

"H"      81.5506781720407     95.0026076040202

"H"      76.3967320422055     103.850552546974

"H"      66.3860912044404     96.1050649249645

"H"      71.7828136652184     98.8202510467998

"H"      84.2549526533081     106.336557141295

"H"      70.1311383417121     95.0846951377353

"H"      80.7912474918762     98.2773869533198

"H"      76.047271924024       100.739170662803

"H"      77.4444336257108     106.578018938175

"H"      78.216722753712       92.1080940821805

"H"      98.1131871263548     96.5348577181837

"H"      79.8096060582027     110.133555887596

"H"      96.6967184378514     112.655383209776

"H"      88.0590278879205     100.8475782767

"H"      75.3620764791804     86.7581104142021

"H"      75.167553970508       98.5108600870843

"H"      76.0533608387299     103.854055038211

"H"      89.1640830625566     103.460664502517

"H"      84.2291076462943     101.371281511854

"H"      81.543926097268       93.3966711072

"H"      74.1052132082048     108.172523985271

"H"      82.2769779377365     100.979772609072

"H"      86.5334471287667     96.0730892386338

"H"      88.1906073268368     98.83369991077

"H"      85.5181215496985     108.014315105923

"H"      88.7783127233874     101.888426904661

"H"      69.4789234909459     98.7012193655892

"H"      78.8106482023447     94.9446650233229

"H"      74.8173742597293     84.6539940584598

"H"      84.5057368248209     103.193352401508

"H"      76.371500963937       89.6957497603508

"H"      80.2952828626344     94.3280771442474

"H"      85.0831360905556     98.2738115630977

"H"      75.3587174763905     100.101776763099

"H"      78.570560554852       95.2622486655099

"H"      77.9868100560937     100.69619862634

"H"      79.4581652428683     101.956156960603

"H"      73.824079359456       92.8280444449172

"H"      85.1017470197075     93.8891491500661

"H"      90.2462571973352     108.852303386528

"H"      82.3598810860348     108.05373345483

"H"      80.8353137858309     101.127107741328

"H"      70.0084615402087     92.4528889364145

"H"      75.4064629154559     105.504975599975

"H"      75.3660531794245     89.0397355560169

"H"      75.4064375306607     97.3858733900471

"H"      81.3758348440165     108.04614270501

"H"      86.4585966439555     114.108118456136

"L"       99.4278972636023     103.369356472034

"L"       72.1852992077221     100.892017027264

"L"       77.4987321223901     99.0385558239805

"L"       76.0944518009138     116.894124399108

"L"       74.5490371082155     99.1052196434577

"L"       77.8351902197669     104.556903570634

"L"       72.6849565982833     96.4531509386966

"L"       73.2411197520153     101.733944692184

"L"       67.6233553837664     84.8570735018949

"L"       85.9842695395919     88.9723085417578

"L"       87.7298229704586     102.098988628201

"L"       83.314975203356       90.1374865363838

"L"       74.7231556124424     99.7721740331776

"L"       79.9512473112294     92.6129267780519

"L"       65.4832568015402     106.169256110979

"L"       81.8852990603768     101.999551527767

"L"       87.1239258021943     101.259269579844

"L"       77.1770913136411     106.568968400335

"L"       82.2984607232772     102.278523270347

"L"       81.221126231544       92.875242427545

"L"       72.6643265026669     94.3406022803352

"L"       90.6474792575588     109.414083317014

"L"       94.7845997048551     110.511872335468

"L"       81.8273182701887     104.55685940814

"L"       76.692497841251       94.9457860231789

"L"       66.4847738486431     112.427769849985

"L"       71.8316862187124     98.7263126078931

"L"       70.8322981149633     103.912117901611

"L"       79.9310536844582     101.075568327062

"L"       73.0311397839799     99.9249057004655

"L"       80.8143481853481     92.0503788323416

"L"       83.1027484212229     101.682739588363

"L"       74.3407209174856     108.7412774034

"L"       83.3326629059945     101.812500157414

"L"       64.9142547375099     98.8209884594929

"L"       66.5451053979331     95.5980314711248

"L"       82.8591957891327     97.4804057095497

"L"       80.9957806904377     99.987891766817

"L"       70.5609408233852     84.6712977629876

"L"       79.2738228785367     101.681030707156

"L"       64.2198763824803     90.0142555201387

"L"       73.5602980881805     108.685278067216

"L"       77.6960641729031     105.425209769558

"L"       74.8913246853889     97.2605392527394

"L"       64.0184276373859     100.818129228064

"L"       81.3086517636691     109.776393773981

"L"       82.9608818763223     106.335768097357

"L"       80.9014151733194     104.912236178188

"L"       68.55919947721         97.1929561379092

"L"       79.1401154697044     104.085861906385

Background

Invasive species can sometimes can spread quickly over new territories, while simultaneously affecting the native fauna and flora. The Asian House Gecko (Hemidactylus frenatus) is an invasive reptile that has spread over most of Eastern and Northern Australia during the past 50 years. Hemidactylus frenatus is known to outcompete native geckos because it is faster at catching prey. However, temperature is known to generally affect locomotion in ectotherms, so it is unclear whether H. frenatus’ speed and competitive ability varies across its range. This information would be valuable for management practices and for predicting further spread under climate change.

Aim

Researchers at an Australian university decided to investigate the effects of temperature on running speed in one population of H. frenatus. 100 individuals were collected and randomly assigned in equal numbers to either a high (32oC) or low (25oC) temperature treatment. Temperature is coded as H (high) or L (low). Running speed was measured using a running wheel over a period of three minutes. A computer measured the number of revolutions in the three minutes travelled by each gecko (rpm). With this information the researchers calculated the running speed of each animal. Because body size also covaries with running speed, they measured body size (mm) just before randomly allocating each gecko to one of the two temperature treatments. Each experiment was conducted approximately at the same time of day over a period of two weeks.

Answer 1

Prove whether temperature affects running speed in the Asian House Gecko via statistical analyses of data (tab-delimited format).

Ans:

Two-sample T for speed

temperature N Mean StDev SE Mean
H 50 80.19 6.89 0.97
L 50 77.42 7.68 1.1

Difference = mu (H) - mu (L)
Estimate for difference: 2.77
95% CI for difference: (-0.12, 5.67)
T-Test of difference = 0 (vs not =): T-Value = 1.90 P-Value = 0.060 DF = 98
Both use Pooled StDev = 7.2936

Comment: The estimated p-value is 0.060 and larger than 0.05 level of significance. Hence, temperature doest not affect running speed in the Asian House Gecko at 0.05 level of significance.