genetic drift - 2026 ACF Regionals

Packet A: Tossup 5

This is the only phenomenon active in a model that uses the expression negative natural log of one minus theta to estimate Reynolds’s distance. Michael Lynch’s barrier hypothesis is partially named after this phenomenon, which is modeled backwards in time to determine coalescence events. (10[1])The null hypothesis for the McDonald–Kreitman test (10[1])states that this phenomenon predominates, (10[1])in accordance with Kimura’s (-5[1])neutral theory. (10[4]-5[2])This phenomenon explains (10[1]-5[1])why (-5[1])the (10[1])time to fixation for an allele is proportional to effective population (10[1])size in the Wright–Fisher (10[2])model for it. (10[1])Pioneer (10[1]-5[1])species are (10[1])subject (10[1])intensely (10[3])to (-5[1])the (10[1])founder effect, (10[3]-5[3])a form (10[2])of (10[1])this phenomenon (10[5]-5[1])that also (10[1]-5[1])manifests (10[2])during (10[2]-5[2])population (10[1]-5[1])bottlenecks. (10[6]-5[5])For 10 points, (10[1]-5[2])name this (10[1])phenomenon where allele distributions (10[1])change randomly. (10[1])■END■ (10[22]0[18])

ANSWER: genetic drift [accept neutral drift; accept random drift; accept allele drift or allelic drift; accept drift-barrier hypothesis; accept Wright effect until read; accept founder effect until read; accept population bottlenecks until read; prompt on neutral mutations or random mutations; prompt on neutral theory or neutral evolution]

<AL, Biology> | Packet A - Brown A, Wisconsin A, Purdue, Maryland B

= Average correct buzzpoint

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Buzzes

Player	Team	Opponent	Buzzpoint	Value
Sinecio Morales	Johns Hopkins A	Columbia C	43	10
Krishna Girish	Montpellier	Cambridge A	50	10
Swapnil Garg	Berkeley A	Stanford A	55	10
Russell Nip	UBC A	Ottawa	59	-5
Kaiwen Xiao	UCLA A	UCSD A	61	-5
Pace Klein	CWRU A	Michigan A	61	-5
Andrew Wang	Illinois A	Indiana C	61	10
Tianyu Xu	Georgia Tech B	Tennessee B	61	10
Matthew Sumanen	Georgia Tech C	Sewanee	61	10
Cade Reinberger	RIT	Binghamton B	61	10
Gary Lin	UCSD C	UCLA B	64	10
Ezra Santos	Chicago A	Northwestern C	64	-5
Snehan Saroch	Louisville A	Bruin	65	-5
Matthew He	Texas A	Texas A&M A	66	10
Vinu Harihar	Berkeley B	Berkeley D	77	10
Akshay Seetharam	Claremont	Missouri B	81	10
Delia Cropper	Oxford A	Edinburgh B	81	10
Vikshar Athreya	Rutgers A	NYU C	84	10
Alden Thompson	Carleton University	Guelph	85	-5
Caleb Ott	Waterloo A	Queen's	85	10
Teigue Kelly	Penn State	Cornell B	87	10
Chris Yoo	William and Mary	Virginia Tech A	88	10
Shiva Tequila	Central Florida A	Florida B	89	10
Nihal Jacob	Kentucky	Alabama B	89	10
Alan Li	Cornell C	Rochester	89	10
Caleb Slusher	South Carolina A	Liberty C	90	-5
Braxton Davis	Missouri A	Iowa State	91	10
Amir Dolansky	Toronto E	McGill A	93	-5
Jason Thieu	Michigan State	Ohio State C	93	10
Alex Akridge	Indiana A	Chicago E	93	10
Alex Baker	Cambridge B	Oxford B	93	-5
Ella Warde	Warwick A	Oxford C	93	10
Olin Bose	Columbia B	Maryland A	93	-5
Wyatt Johnson	CWRU B	Michigan C	95	10
Tiffany Zhou	Ohio State A	Ohio State B	95	10
Dennis Reppen	Imperial A	City St. George's	96	10
March Delfin	UCSD B	UC Irvine	98	10
Nicholas Nguyen	Florida A	Central Florida B	98	10
Emily Kadolph	Virginia Tech B	Wake Forest	98	10
Sasha Tripathi	Chicago C	Indiana B	98	10
Kai Madgwick	Manchester	Imperial B	98	-5
Jerry Vinokurov	John Jay	Swarthmore	98	10
Kevin Ye	Simon Fraser	Western C	100	10
Jacob Finley	Notre Dame A	Purdue B	100	-5
Kaiden Webb	Chicago D	Illinois C	101	10
Kelvin Ni	NYU B	Johns Hopkins B	101	10
Abbott Sherwin	NC State A	North Carolina A	102	-5
Aden Sun	Chicago B	Notre Dame B	102	10
Nathan Woolery	Louisville B	WashU A	102	10
Andrew Miller	Binghamton A	Cornell A	102	-5
Travis Johnson	Pittsburgh	Michigan B	103	10
Carson Kessler	Washington B	Minnesota A	103	-5
Carter Yott	McMaster A	Toronto B	104	-5
Connor Ronan	South Carolina B	Duke	104	10
Fern Fang	VCU	Liberty B	104	-5
Timothy Chiu	Northwestern D	Illinois B	104	10
Rohan Dalal	Georgia Tech A	Carleton College	104	10
Parker McCoig	Tennessee A	Vanderbilt B	104	10
Ted Warner	Bristol	Cambridge C	104	10
Ali Hamzeh	Edinburgh A	Southampton A	104	10
Henry Jameson	LSE	Imperial C	104	-5
Andrew Massaro	Catholic	Maryland C	104	-5
Evan Schleck	Georgetown	NYU A	104	-5
Ethen Sun	Toronto D	Toronto F	107	-5
Keerthana Krishnan	Texas B	Murray State A	107	10
Mark Tawfik	Rutgers B	Vassar	107	-5
Camden Walker	WashU B	Georgia Tech D	109	10
Winston Zuo	UC Santa Barbara	Arizona State	113	10
Abby Smith	Berkeley C	Stanford B	115	10
Fish Tsai	UCSD A	UCLA A	116	10
Victor Xu	Toronto G	Brock	116	10
Eva Mandelbaum	Guelph	Carleton University	116	10
Raymond Chen	Toronto B	McMaster A	116	10
Yusuf Baig	McMaster B	Western B	116	0
Dustin Vali	Western B	McMaster B	116	0
Franklin Wu	Toronto C	McGill B	116	0
Luke Sloan	McGill B	Toronto C	116	0
Cameron Liu	Toronto F	Toronto D	116	10
Ava Butler	McGill A	Toronto E	116	10
Colin Veevers	Ottawa	UBC A	116	10
Prabhjot Chopra	Waterloo B	UBC B	116	10
Ishan Joshi	Toronto Metropolitan	Western A	116	10
Adam Jarvis	Florida C	Central Florida C	116	0
Anna Barker	Central Florida C	Florida C	116	0
Joshua Koch	Michigan A	CWRU A	116	10
Neal Sengupta	North Carolina C	James Madison B	116	0
Summer Solis	James Madison B	North Carolina C	116	0
Nathan Redford	Liberty A	NC State B	116	10
Joseph Cole	North Carolina A	NC State A	116	10
Diego Almaraz	North Carolina B	James Madison A	116	10
Katie Young	Liberty C	South Carolina A	116	0
Abby Keith	Liberty B	VCU	116	0
Cooper Stringer	Northwestern C	Chicago A	116	10
Davis Johnson	Purdue B	Notre Dame A	116	10
Foster Hughes	Minnesota A	Washington B	116	10
Jack Lewis	Bruin	Louisville A	116	10
Teddy Fogel	Birmingham	Cardiff	116	0
Harri Slaughter	Cardiff	Birmingham	116	10
Rafael Castro	Imperial C	LSE	116	10
Nathan Long	Imperial B	Manchester	116	0
Aisling Skeet	Durham	UCL	116	0
Imran Abdul Rahman	UCL	Durham	116	0
Danny Fisher	Warwick B	Southampton B	116	0
Zosia Mikolajczuk	Southampton B	Warwick B	116	10
Gus Vanskike	Maryland C	Catholic	116	0
Andy Yu	Maryland A	Columbia B	116	10
Ryan Rosenberg	NYU A	Georgetown	116	10
Eli Young	Vassar	Rutgers B	116	0
Jackie Xu	Cornell A	Binghamton A	116	0

Summary

Tournament	Edition	Match	Heard	Conv. %	Neg %	Avg. Buzz
California (North)	Main Site	✓	3	100%	0%	82.33
California (South)	Main Site	✓	4	100%	25%	97.75
Canada	Main Site	✓	12	83%	42%	111.30
Florida	Main Site	✓	3	67%	0%	93.50
Great Lakes	Main Site	✓	5	100%	20%	100.40
Lower Mid-Atlantic	Main Site	✓	9	67%	33%	106.33
Midwest	Main Site	✓	8	100%	25%	98.88
Overflow	Main Site	✓	4	100%	25%	98.00
South Central	Main Site	✓	2	100%	0%	86.50
Southeast	Main Site	✓	7	100%	14%	91.71
UK	Main Site	✓	12	75%	25%	97.33
Upper Mid-Atlantic	Main Site	✓	8	75%	50%	93.00
Upstate NY	Main Site	✓	4	75%	25%	79.00